diff --git a/zig/src/http/handler.zig b/zig/src/http/handler.zig
index 308b731..3d7f2b4 100644
--- a/zig/src/http/handler.zig
+++ b/zig/src/http/handler.zig
@@ -4,6 +4,7 @@ const Cache = @import("../cache/cache.zig").Cache;
 const WeatherProvider = @import("../weather/provider.zig").WeatherProvider;
 const Resolver = @import("../location/resolver.zig").Resolver;
 const Location = @import("../location/resolver.zig").Location;
+const QueryParams = @import("query.zig").QueryParams;
 const ansi = @import("../render/ansi.zig");
 const line = @import("../render/line.zig");
 const json = @import("../render/json.zig");
@@ -130,21 +131,27 @@ fn handleWeatherInternal(
     };
     defer weather.deinit();
 
-    const query = try req.query();
-    const format = query.get("format");
+    const query_string = req.url.query;
+    const params = try QueryParams.parse(allocator, query_string);
+    defer {
+        if (params.format) |f| allocator.free(f);
+        if (params.lang) |l| allocator.free(l);
+    }
 
-    const output = if (format) |fmt| blk: {
+    const use_imperial = if (params.units) |u| u == .uscs else false;
+
+    const output = if (params.format) |fmt| blk: {
         if (std.mem.eql(u8, fmt, "j1")) {
             res.content_type = .JSON;
             break :blk try json.render(allocator, weather);
         } else if (std.mem.eql(u8, fmt, "v2")) {
-            break :blk try v2.render(allocator, weather);
+            break :blk try v2.render(allocator, weather, use_imperial);
         } else if (std.mem.startsWith(u8, fmt, "%")) {
-            break :blk try custom.render(allocator, weather, fmt);
+            break :blk try custom.render(allocator, weather, fmt, use_imperial);
         } else {
-            break :blk try line.render(allocator, weather, fmt);
+            break :blk try line.render(allocator, weather, fmt, use_imperial);
         }
-    } else try ansi.render(allocator, weather, .{});
+    } else try ansi.render(allocator, weather, .{ .use_imperial = use_imperial });
 
     const ttl = 1000 + std.crypto.random.intRangeAtMost(u64, 0, 1000);
     try opts.cache.put(cache_key, output, ttl);
@@ -161,12 +168,11 @@ fn generateCacheKey(
     location: ?[]const u8,
 ) ![]const u8 {
     const loc = location orelse "";
-    const query = try req.query();
-    const format = query.get("format") orelse "";
+    const query_string = req.url.query;
     return std.fmt.allocPrint(allocator, "{s}:{s}:{s}", .{
         req.url.path,
         loc,
-        format,
+        query_string,
     });
 }
 
diff --git a/zig/src/http/query.zig b/zig/src/http/query.zig
index 0a27c73..d6e042e 100644
--- a/zig/src/http/query.zig
+++ b/zig/src/http/query.zig
@@ -59,6 +59,23 @@ test "parse format parameter" {
     try std.testing.expectEqualStrings("j1", params.format.?);
 }
 
+test "parse units with question mark" {
+    const allocator = std.testing.allocator;
+
+    // Test with just "u" (no question mark in query string)
+    const params1 = try QueryParams.parse(allocator, "u");
+    try std.testing.expectEqual(QueryParams.Units.uscs, params1.units.?);
+
+    // Test with "u=" (empty value)
+    const params2 = try QueryParams.parse(allocator, "u=");
+    try std.testing.expectEqual(QueryParams.Units.uscs, params2.units.?);
+
+    // Test combined with other params
+    const params3 = try QueryParams.parse(allocator, "format=3&u");
+    defer if (params3.format) |f| allocator.free(f);
+    try std.testing.expectEqual(QueryParams.Units.uscs, params3.units.?);
+}
+
 test "parse units parameters" {
     const allocator = std.testing.allocator;
     const params_m = try QueryParams.parse(allocator, "m");
@@ -66,6 +83,9 @@ test "parse units parameters" {
 
     const params_u = try QueryParams.parse(allocator, "u");
     try std.testing.expectEqual(QueryParams.Units.uscs, params_u.units.?);
+
+    const params_u_query = try QueryParams.parse(allocator, "u=");
+    try std.testing.expectEqual(QueryParams.Units.uscs, params_u_query.units.?);
 }
 
 test "parse multiple parameters" {
diff --git a/zig/src/render/ansi.zig b/zig/src/render/ansi.zig
index 88b941b..831566f 100644
--- a/zig/src/render/ansi.zig
+++ b/zig/src/render/ansi.zig
@@ -27,3 +27,27 @@ pub fn render(allocator: std.mem.Allocator, data: types.WeatherData, options: Re
 
     return output.toOwnedSlice(allocator);
 }
+
+test "render with imperial units" {
+    const data = types.WeatherData{
+        .location = "Chicago",
+        .current = .{
+            .temp_c = 10.0,
+            .temp_f = 50.0,
+            .condition = "Clear",
+            .weather_code = 113,
+            .humidity = 60,
+            .wind_kph = 16.0,
+            .wind_dir = "N",
+            .pressure_mb = 1013.0,
+            .precip_mm = 0.0,
+        },
+        .forecast = &.{},
+        .allocator = std.testing.allocator,
+    };
+
+    const output = try render(std.testing.allocator, data, .{ .use_imperial = true });
+    defer std.testing.allocator.free(output);
+
+    try std.testing.expect(std.mem.indexOf(u8, output, "50.0°F") != null);
+}
diff --git a/zig/src/render/custom.zig b/zig/src/render/custom.zig
index b591d8f..4b2cb36 100644
--- a/zig/src/render/custom.zig
+++ b/zig/src/render/custom.zig
@@ -13,7 +13,7 @@ fn getWeatherIcon(code: u16) []const u8 {
     return weather_icons[idx];
 }
 
-pub fn render(allocator: std.mem.Allocator, weather: types.WeatherData, format: []const u8) ![]const u8 {
+pub fn render(allocator: std.mem.Allocator, weather: types.WeatherData, format: []const u8, use_imperial: bool) ![]const u8 {
     var output: std.ArrayList(u8) = .empty;
     errdefer output.deinit(allocator);
     const writer = output.writer(allocator);
@@ -26,12 +26,32 @@ pub fn render(allocator: std.mem.Allocator, weather: types.WeatherData, format:
                 'c' => try writer.print("{s}", .{getWeatherIcon(weather.current.weather_code)}),
                 'C' => try writer.print("{s}", .{weather.current.condition}),
                 'h' => try writer.print("{d}%", .{weather.current.humidity}),
-                't' => try writer.print("{d:.0}°C", .{weather.current.temp_c}),
-                'f' => try writer.print("{d:.0}°C", .{weather.current.temp_c}), // Feels like (same as temp for now)
-                'w' => try writer.print("{d:.0} km/h {s}", .{ weather.current.wind_kph, weather.current.wind_dir }),
+                't' => {
+                    const temp = if (use_imperial) weather.current.temp_f else weather.current.temp_c;
+                    const unit = if (use_imperial) "°F" else "°C";
+                    try writer.print("{d:.0}{s}", .{ temp, unit });
+                },
+                'f' => {
+                    const temp = if (use_imperial) weather.current.temp_f else weather.current.temp_c;
+                    const unit = if (use_imperial) "°F" else "°C";
+                    try writer.print("{d:.0}{s}", .{ temp, unit });
+                },
+                'w' => {
+                    const wind = if (use_imperial) weather.current.wind_kph * 0.621371 else weather.current.wind_kph;
+                    const unit = if (use_imperial) "mph" else "km/h";
+                    try writer.print("{d:.0} {s} {s}", .{ wind, unit, weather.current.wind_dir });
+                },
                 'l' => try writer.print("{s}", .{weather.location}),
-                'p' => try writer.print("{d:.1} mm", .{weather.current.precip_mm}),
-                'P' => try writer.print("{d:.0} hPa", .{weather.current.pressure_mb}),
+                'p' => {
+                    const precip = if (use_imperial) weather.current.precip_mm * 0.0393701 else weather.current.precip_mm;
+                    const unit = if (use_imperial) "in" else "mm";
+                    try writer.print("{d:.1} {s}", .{ precip, unit });
+                },
+                'P' => {
+                    const pressure = if (use_imperial) weather.current.pressure_mb * 0.02953 else weather.current.pressure_mb;
+                    const unit = if (use_imperial) "inHg" else "hPa";
+                    try writer.print("{d:.2} {s}", .{ pressure, unit });
+                },
                 'm' => try writer.print("🌕", .{}), // Moon phase placeholder
                 'M' => try writer.print("15", .{}), // Moon day placeholder
                 'o' => try writer.print("0%", .{}), // Probability of precipitation placeholder
@@ -76,7 +96,7 @@ test "render custom format with location and temp" {
         .allocator = allocator,
     };
 
-    const output = try render(allocator, weather, "%l: %c %t");
+    const output = try render(allocator, weather, "%l: %c %t", false);
     defer allocator.free(output);
 
     try std.testing.expect(std.mem.indexOf(u8, output, "London") != null);
@@ -103,7 +123,7 @@ test "render custom format with newline" {
         .allocator = allocator,
     };
 
-    const output = try render(allocator, weather, "%l%n%C");
+    const output = try render(allocator, weather, "%l%n%C", false);
     defer allocator.free(output);
 
     try std.testing.expect(std.mem.indexOf(u8, output, "Paris\nClear") != null);
@@ -129,9 +149,37 @@ test "render custom format with humidity and pressure" {
         .allocator = allocator,
     };
 
-    const output = try render(allocator, weather, "Humidity: %h, Pressure: %P");
+    const output = try render(allocator, weather, "Humidity: %h, Pressure: %P", false);
     defer allocator.free(output);
 
     try std.testing.expect(std.mem.indexOf(u8, output, "85%") != null);
     try std.testing.expect(std.mem.indexOf(u8, output, "1012") != null);
 }
+
+test "render custom format with imperial units" {
+    const allocator = std.testing.allocator;
+
+    const weather = types.WeatherData{
+        .location = "NYC",
+        .current = .{
+            .temp_c = 10.0,
+            .temp_f = 50.0,
+            .condition = "Clear",
+            .weather_code = 113,
+            .humidity = 60,
+            .wind_kph = 16.0,
+            .wind_dir = "N",
+            .pressure_mb = 1013.0,
+            .precip_mm = 2.5,
+        },
+        .forecast = &[_]types.ForecastDay{},
+        .allocator = allocator,
+    };
+
+    const output = try render(allocator, weather, "%t %w %p", true);
+    defer allocator.free(output);
+
+    try std.testing.expect(std.mem.indexOf(u8, output, "50°F") != null);
+    try std.testing.expect(std.mem.indexOf(u8, output, "mph") != null);
+    try std.testing.expect(std.mem.indexOf(u8, output, "in") != null);
+}
diff --git a/zig/src/render/line.zig b/zig/src/render/line.zig
index 10aa141..288b214 100644
--- a/zig/src/render/line.zig
+++ b/zig/src/render/line.zig
@@ -1,51 +1,72 @@
 const std = @import("std");
 const types = @import("../weather/types.zig");
 
-pub fn render(allocator: std.mem.Allocator, data: types.WeatherData, format: []const u8) ![]const u8 {
+pub fn render(allocator: std.mem.Allocator, data: types.WeatherData, format: []const u8, use_imperial: bool) ![]const u8 {
     if (std.mem.eql(u8, format, "1")) {
-        return std.fmt.allocPrint(allocator, "{s}: {s} {d:.0}°C", .{
+        const temp = if (use_imperial) data.current.temp_f else data.current.temp_c;
+        const unit = if (use_imperial) "°F" else "°C";
+        return std.fmt.allocPrint(allocator, "{s}: {s} {d:.0}{s}", .{
             data.location,
             getConditionEmoji(data.current.weather_code),
-            data.current.temp_c,
+            temp,
+            unit,
         });
     } else if (std.mem.eql(u8, format, "2")) {
-        return std.fmt.allocPrint(allocator, "{s}: {s} {d:.0}°C {s}{s}{d:.0}km/h", .{
+        const temp = if (use_imperial) data.current.temp_f else data.current.temp_c;
+        const unit = if (use_imperial) "°F" else "°C";
+        const wind = if (use_imperial) data.current.wind_kph * 0.621371 else data.current.wind_kph;
+        const wind_unit = if (use_imperial) "mph" else "km/h";
+        return std.fmt.allocPrint(allocator, "{s}: {s} {d:.0}{s} {s}{s}{d:.0}{s}", .{
             data.location,
             getConditionEmoji(data.current.weather_code),
-            data.current.temp_c,
+            temp,
+            unit,
             "🌬️",
             data.current.wind_dir,
-            data.current.wind_kph,
+            wind,
+            wind_unit,
         });
     } else if (std.mem.eql(u8, format, "3")) {
-        return std.fmt.allocPrint(allocator, "{s}: {s} {d:.0}°C {s}{s}{d:.0}km/h {s}{d}%%", .{
+        const temp = if (use_imperial) data.current.temp_f else data.current.temp_c;
+        const unit = if (use_imperial) "°F" else "°C";
+        const wind = if (use_imperial) data.current.wind_kph * 0.621371 else data.current.wind_kph;
+        const wind_unit = if (use_imperial) "mph" else "km/h";
+        return std.fmt.allocPrint(allocator, "{s}: {s} {d:.0}{s} {s}{s}{d:.0}{s} {s}{d}%%", .{
             data.location,
             getConditionEmoji(data.current.weather_code),
-            data.current.temp_c,
+            temp,
+            unit,
             "🌬️",
             data.current.wind_dir,
-            data.current.wind_kph,
+            wind,
+            wind_unit,
             "💧",
             data.current.humidity,
         });
     } else if (std.mem.eql(u8, format, "4")) {
-        return std.fmt.allocPrint(allocator, "{s}: {s} {d:.0}°C {s}{s}{d:.0}km/h {s}{d}%% {s}", .{
+        const temp = if (use_imperial) data.current.temp_f else data.current.temp_c;
+        const unit = if (use_imperial) "°F" else "°C";
+        const wind = if (use_imperial) data.current.wind_kph * 0.621371 else data.current.wind_kph;
+        const wind_unit = if (use_imperial) "mph" else "km/h";
+        return std.fmt.allocPrint(allocator, "{s}: {s} {d:.0}{s} {s}{s}{d:.0}{s} {s}{d}%% {s}", .{
             data.location,
             getConditionEmoji(data.current.weather_code),
-            data.current.temp_c,
+            temp,
+            unit,
             "🌬️",
             data.current.wind_dir,
-            data.current.wind_kph,
+            wind,
+            wind_unit,
             "💧",
             data.current.humidity,
             "☀️",
         });
     } else {
-        return renderCustom(allocator, data, format);
+        return renderCustom(allocator, data, format, use_imperial);
     }
 }
 
-fn renderCustom(allocator: std.mem.Allocator, data: types.WeatherData, format: []const u8) ![]const u8 {
+fn renderCustom(allocator: std.mem.Allocator, data: types.WeatherData, format: []const u8, use_imperial: bool) ![]const u8 {
     var output: std.ArrayList(u8) = .empty;
     errdefer output.deinit(allocator);
 
@@ -57,12 +78,28 @@ fn renderCustom(allocator: std.mem.Allocator, data: types.WeatherData, format: [
                 'c' => try output.appendSlice(allocator, getConditionEmoji(data.current.weather_code)),
                 'C' => try output.appendSlice(allocator, data.current.condition),
                 'h' => try output.writer(allocator).print("{d}", .{data.current.humidity}),
-                't' => try output.writer(allocator).print("{d:.0}", .{data.current.temp_c}),
-                'f' => try output.writer(allocator).print("{d:.0}", .{data.current.temp_c}),
-                'w' => try output.writer(allocator).print("{s}{d:.0}km/h", .{ data.current.wind_dir, data.current.wind_kph }),
+                't' => {
+                    const temp = if (use_imperial) data.current.temp_f else data.current.temp_c;
+                    try output.writer(allocator).print("{d:.0}", .{temp});
+                },
+                'f' => {
+                    const temp = if (use_imperial) data.current.temp_f else data.current.temp_c;
+                    try output.writer(allocator).print("{d:.0}", .{temp});
+                },
+                'w' => {
+                    const wind = if (use_imperial) data.current.wind_kph * 0.621371 else data.current.wind_kph;
+                    const wind_unit = if (use_imperial) "mph" else "km/h";
+                    try output.writer(allocator).print("{s}{d:.0}{s}", .{ data.current.wind_dir, wind, wind_unit });
+                },
                 'l' => try output.appendSlice(allocator, data.location),
-                'p' => try output.writer(allocator).print("{d:.1}", .{data.current.precip_mm}),
-                'P' => try output.writer(allocator).print("{d:.0}", .{data.current.pressure_mb}),
+                'p' => {
+                    const precip = if (use_imperial) data.current.precip_mm * 0.0393701 else data.current.precip_mm;
+                    try output.writer(allocator).print("{d:.1}", .{precip});
+                },
+                'P' => {
+                    const pressure = if (use_imperial) data.current.pressure_mb * 0.02953 else data.current.pressure_mb;
+                    try output.writer(allocator).print("{d:.0}", .{pressure});
+                },
                 '%' => try output.append(allocator, '%'),
                 else => {
                     try output.append(allocator, '%');
@@ -112,7 +149,7 @@ test "format 1" {
         .allocator = std.testing.allocator,
     };
 
-    const output = try render(std.testing.allocator, data, "1");
+    const output = try render(std.testing.allocator, data, "1", false);
     defer std.testing.allocator.free(output);
 
     try std.testing.expectEqualStrings("London: ☀️ 15°C", output);
@@ -136,8 +173,32 @@ test "custom format" {
         .allocator = std.testing.allocator,
     };
 
-    const output = try render(std.testing.allocator, data, "%l: %c %t°C");
+    const output = try render(std.testing.allocator, data, "%l: %c %t°C", false);
     defer std.testing.allocator.free(output);
 
     try std.testing.expectEqualStrings("London: ☀️ 15°C", output);
 }
+
+test "format 2 with imperial units" {
+    const data = types.WeatherData{
+        .location = "Portland",
+        .current = .{
+            .temp_c = 10.0,
+            .temp_f = 50.0,
+            .condition = "Cloudy",
+            .weather_code = 119,
+            .humidity = 70,
+            .wind_kph = 20.0,
+            .wind_dir = "SE",
+            .pressure_mb = 1013.0,
+            .precip_mm = 0.0,
+        },
+        .forecast = &.{},
+        .allocator = std.testing.allocator,
+    };
+
+    const output = try render(std.testing.allocator, data, "2", true);
+    defer std.testing.allocator.free(output);
+
+    try std.testing.expectEqualStrings("Portland: ☁️ 50°F 🌬️SE12mph", output);
+}
diff --git a/zig/src/render/v2.zig b/zig/src/render/v2.zig
index 98216ca..6099c5d 100644
--- a/zig/src/render/v2.zig
+++ b/zig/src/render/v2.zig
@@ -1,7 +1,7 @@
 const std = @import("std");
 const types = @import("../weather/types.zig");
 
-pub fn render(allocator: std.mem.Allocator, weather: types.WeatherData) ![]const u8 {
+pub fn render(allocator: std.mem.Allocator, weather: types.WeatherData, use_imperial: bool) ![]const u8 {
     var output: std.ArrayList(u8) = .empty;
     errdefer output.deinit(allocator);
     const writer = output.writer(allocator);
@@ -13,15 +13,34 @@ pub fn render(allocator: std.mem.Allocator, weather: types.WeatherData) ![]const
     try writer.print("      Current conditions\n", .{});
     try writer.print("      {s}\n", .{weather.current.condition});
     try writer.writeAll("      🌡️  ");
-    try writer.print("{d:.1}°C ({d:.1}°F)\n", .{ weather.current.temp_c, weather.current.temp_f });
+    if (use_imperial) {
+        try writer.print("{d:.1}°F\n", .{weather.current.temp_f});
+    } else {
+        try writer.print("{d:.1}°C ({d:.1}°F)\n", .{ weather.current.temp_c, weather.current.temp_f });
+    }
     try writer.writeAll("      💧 ");
     try writer.print("{d}%\n", .{weather.current.humidity});
     try writer.writeAll("      🌬️  ");
-    try writer.print("{d:.1} km/h {s}\n", .{ weather.current.wind_kph, weather.current.wind_dir });
+    if (use_imperial) {
+        const wind_mph = weather.current.wind_kph * 0.621371;
+        try writer.print("{d:.1} mph {s}\n", .{ wind_mph, weather.current.wind_dir });
+    } else {
+        try writer.print("{d:.1} km/h {s}\n", .{ weather.current.wind_kph, weather.current.wind_dir });
+    }
     try writer.writeAll("      🔽 ");
-    try writer.print("{d:.1} hPa\n", .{weather.current.pressure_mb});
+    if (use_imperial) {
+        const pressure_inhg = weather.current.pressure_mb * 0.02953;
+        try writer.print("{d:.2} inHg\n", .{pressure_inhg});
+    } else {
+        try writer.print("{d:.1} hPa\n", .{weather.current.pressure_mb});
+    }
     try writer.writeAll("      💦 ");
-    try writer.print("{d:.1} mm\n\n", .{weather.current.precip_mm});
+    if (use_imperial) {
+        const precip_in = weather.current.precip_mm * 0.0393701;
+        try writer.print("{d:.2} in\n\n", .{precip_in});
+    } else {
+        try writer.print("{d:.1} mm\n\n", .{weather.current.precip_mm});
+    }
 
     // Forecast
     if (weather.forecast.len > 0) {
@@ -29,9 +48,19 @@ pub fn render(allocator: std.mem.Allocator, weather: types.WeatherData) ![]const
         for (weather.forecast) |day| {
             try writer.print("      {s}: {s}\n", .{ day.date, day.condition });
             try writer.writeAll("      ↑ ");
-            try writer.print("{d:.1}°C  ", .{day.max_temp_c});
+            if (use_imperial) {
+                const max_f = day.max_temp_c * 9.0 / 5.0 + 32.0;
+                try writer.print("{d:.1}°F  ", .{max_f});
+            } else {
+                try writer.print("{d:.1}°C  ", .{day.max_temp_c});
+            }
             try writer.writeAll("↓ ");
-            try writer.print("{d:.1}°C\n", .{day.min_temp_c});
+            if (use_imperial) {
+                const min_f = day.min_temp_c * 9.0 / 5.0 + 32.0;
+                try writer.print("{d:.1}°F\n", .{min_f});
+            } else {
+                try writer.print("{d:.1}°C\n", .{day.min_temp_c});
+            }
         }
     }
 
@@ -58,7 +87,7 @@ test "render v2 format" {
         .allocator = allocator,
     };
 
-    const output = try render(allocator, weather);
+    const output = try render(allocator, weather, false);
     defer allocator.free(output);
 
     try std.testing.expect(output.len > 0);
@@ -66,3 +95,31 @@ test "render v2 format" {
     try std.testing.expect(std.mem.indexOf(u8, output, "Current conditions") != null);
     try std.testing.expect(std.mem.indexOf(u8, output, "12.0°C") != null);
 }
+
+test "render v2 format with imperial units" {
+    const allocator = std.testing.allocator;
+
+    const weather = types.WeatherData{
+        .location = "Boston",
+        .current = .{
+            .temp_c = 10.0,
+            .temp_f = 50.0,
+            .condition = "Clear",
+            .weather_code = 113,
+            .humidity = 65,
+            .wind_kph = 16.0,
+            .wind_dir = "N",
+            .pressure_mb = 1013.0,
+            .precip_mm = 0.0,
+        },
+        .forecast = &[_]types.ForecastDay{},
+        .allocator = allocator,
+    };
+
+    const output = try render(allocator, weather, true);
+    defer allocator.free(output);
+
+    try std.testing.expect(std.mem.indexOf(u8, output, "50.0°F") != null);
+    try std.testing.expect(std.mem.indexOf(u8, output, "mph") != null);
+    try std.testing.expect(std.mem.indexOf(u8, output, "inHg") != null);
+}