diff --git a/src/free_api_v25/query/mod.rs b/src/free_api_v25/query/mod.rs
index c8a0f80..4983fae 100644
--- a/src/free_api_v25/query/mod.rs
+++ b/src/free_api_v25/query/mod.rs
@@ -18,5 +18,10 @@
 //! assert!(url.contains("q=London"));
 //! ```
 
+pub mod queryparams;
 pub mod units;
 pub mod urls;
+
+pub use queryparams::*;
+pub use units::*;
+pub use urls::*;
diff --git a/src/free_api_v25/query/queryparams.rs b/src/free_api_v25/query/queryparams.rs
new file mode 100644
index 0000000..d1a0468
--- /dev/null
+++ b/src/free_api_v25/query/queryparams.rs
@@ -0,0 +1,126 @@
+use super::{
+    Units,
+    urls::{FORECAST_URL, WEATHER_URL},
+};
+
+/// Query parameters for `OpenWeatherMap` API.
+///
+/// **Note:** One of `city_id`, `city_name`, `(lat, lon)` pair, or `zip` **must** be provided,
+/// otherwise URL building will fail.
+#[derive(Debug, Clone)]
+pub struct QueryParams {
+    /// Your `OpenWeatherMap` API key
+    pub api_key: String,
+
+    /// City ID (optional)
+    ///
+    /// You can make an API call by city ID to get an unambiguous result for your city.
+    /// The list of city IDs (`city.list.json.gz`) can be downloaded [here](http://bulk.openweathermap.org/sample/).
+    pub city_id: Option<String>,
+
+    /// City name (optional)
+    ///
+    /// You can call by city name, or city name + state code + country code.
+    /// Searching by state is only available for locations in the USA.
+    /// See: <https://openweathermap.org/current#name>
+    pub city_name: Option<String>,
+
+    /// Latitude (optional, must be used with `lon`)
+    pub lat: Option<f32>,
+
+    /// Longitude (optional, must be used with `lat`)
+    pub lon: Option<f32>,
+
+    /// Zip code (optional)
+    ///
+    /// Format: `"94040,us"`. If the country code is not specified, it defaults to USA.
+    pub zip: Option<String>,
+
+    /// Units for temperature and wind (default `"Standard"`)
+    pub units: Units,
+
+    /// Language code for descriptions (default `"en"`)
+    pub lang: String,
+}
+
+impl QueryParams {
+    /// Build query URL for the `/weather` endpoint.
+    ///
+    /// # Errors
+    ///
+    /// Returns an `Err` if no valid location is specified
+    /// (`city_id`, `city_name`, `lat`/`lon`, or `zip` are all None).
+    ///
+    /// # Example
+    ///
+    /// ```
+    /// use owm_api25::query::{QueryParams, Units, WEATHER_URL};
+    ///
+    /// let query = QueryParams {
+    ///     api_key: "MY_API_KEY".to_string(),
+    ///     city_name: Some("London".to_string()),
+    ///     ..Default::default()
+    /// };
+    ///
+    /// let url = query.weather_url().unwrap();
+    /// assert!(url.contains("q=London"));
+    /// assert!(url.contains("appid=MY_API_KEY"));
+    /// ```
+    pub fn weather_url(&self) -> Result<String, String> {
+        self.build_url(WEATHER_URL)
+    }
+
+    /// Build query URL for the `/forecast` endpoint.
+    ///
+    /// # Errors
+    ///
+    /// Returns an `Err` if no valid location is specified.
+    /// See `weather_url`.
+    pub fn forecast_url(&self) -> Result<String, String> {
+        self.build_url(FORECAST_URL)
+    }
+
+    /// Internal helper to build query URL.
+    ///
+    /// # Errors
+    ///
+    /// Returns an `Err` if no valid location is specified (`city_id`, `city_name`, `lat`/`lon`, or `zip`).
+    fn build_url(&self, base: &str) -> Result<String, String> {
+        let mut params = vec![
+            format!("appid={}", self.api_key),
+            format!("units={}", self.units),
+            format!("lang={}", self.lang),
+            "mode=json".to_string(),
+        ];
+
+        if let Some(ref id) = self.city_id {
+            params.push(format!("id={id}"));
+        } else if let Some(ref name) = self.city_name {
+            params.push(format!("q={name}"));
+        } else if let (Some(lat), Some(lon)) = (self.lat, self.lon) {
+            params.push(format!("lat={lat}&lon={lon}"));
+        } else if let Some(ref zip) = self.zip {
+            params.push(format!("zip={zip}"));
+        } else {
+            return Err("No valid location field found".into());
+        }
+
+        Ok(format!("{base}?{}", params.join("&")))
+    }
+}
+
+/// Default values for query parameters
+impl Default for QueryParams {
+    fn default() -> Self {
+        Self {
+            api_key: String::new(),
+            city_id: None,
+            city_name: None,
+            lat: None,
+            lon: None,
+            zip: None,
+            units: Units::Standard,
+            lang: "en".to_string(),
+        }
+    }
+}