WeatherAPI

api.weatherapi.com · Science

Science API Key Free Tier Weather Forecast Climate

Current weather, forecasts, historical weather, marine, astronomy, and air quality for any location. Great documentation. Free tier: 1M calls/month.

Authentication

API Key authentication Free API key at weatherapi.com. Pass as ?key= query parameter.

Sample Requests

GET Current weather

Get current weather and air quality for London.

https://api.weatherapi.com/v1/current.json?q=London&aqi=yes&key=YOUR_KEY

Hover any highlighted part to learn what it does

curl -X GET "https://api.weatherapi.com/v1/current.json?q=London&aqi=yes&key=YOUR_KEY"

import requests
params = {
    "q": "London",
    "aqi": "yes",
    "key": "YOUR_KEY"
}
response = requests.get(
    "https://api.weatherapi.com/v1/current.json",
    params=params,
)
print(response.json())

const url = new URL('https://api.weatherapi.com/v1/current.json');
url.searchParams.set('q', 'London');
url.searchParams.set('aqi', 'yes');
url.searchParams.set('key', 'YOUR_KEY');

const response = await fetch(url); 
const data = await response.json();
console.log(data);

package main

import (
	"fmt"
	"io"
	"net/http"
	"net/url"
)

func main() {
	baseURL, _ := url.Parse("https://api.weatherapi.com/v1/current.json")
	q := baseURL.Query()
	q.Set("q", "London")
	q.Set("aqi", "yes")
	q.Set("key", "YOUR_KEY")
	baseURL.RawQuery = q.Encode()
	targetURL := baseURL.String()
	req, _ := http.NewRequest("GET", targetURL, nil)

	client := &http.Client{}
	resp, _ := client.Do(req)
	defer resp.Body.Close()
	body, _ := io.ReadAll(resp.Body)
	fmt.Println(string(body))
}

require "net/http"
require "json"

uri = URI("https://api.weatherapi.com/v1/current.json")
uri.query = URI.encode_www_form({
  "q" => "London",
  "aqi" => "yes",
  "key" => "YOUR_KEY"
})

http = Net::HTTP.new(uri.host, uri.port)
http.use_ssl = uri.scheme == "https"

req = Net::HTTP::Get.new(uri)

res = http.request(req)
puts JSON.parse(res.body)

<?php
$url = "https://api.weatherapi.com/v1/current.json?" . http_build_query([
    "q" => "London",
    "aqi" => "yes",
    "key" => "YOUR_KEY"
]);
$opts = ["http" => [
    "method" => "GET",
]];
$ctx = stream_context_create($opts);
$res = file_get_contents($url, false, $ctx);
print_r(json_decode($res, true));

GET 3-day forecast

Get 3-day forecast for New York.

https://api.weatherapi.com/v1/forecast.json?q=New York&key=YOUR_KEY&days=3

Hover any highlighted part to learn what it does

curl -X GET "https://api.weatherapi.com/v1/forecast.json?q=New%20York&key=YOUR_KEY&days=3"

import requests
params = {
    "q": "New York",
    "key": "YOUR_KEY",
    "days": "3"
}
response = requests.get(
    "https://api.weatherapi.com/v1/forecast.json",
    params=params,
)
print(response.json())

const url = new URL('https://api.weatherapi.com/v1/forecast.json');
url.searchParams.set('q', 'New York');
url.searchParams.set('key', 'YOUR_KEY');
url.searchParams.set('days', '3');

const response = await fetch(url); 
const data = await response.json();
console.log(data);

package main

import (
	"fmt"
	"io"
	"net/http"
	"net/url"
)

func main() {
	baseURL, _ := url.Parse("https://api.weatherapi.com/v1/forecast.json")
	q := baseURL.Query()
	q.Set("q", "New York")
	q.Set("key", "YOUR_KEY")
	q.Set("days", "3")
	baseURL.RawQuery = q.Encode()
	targetURL := baseURL.String()
	req, _ := http.NewRequest("GET", targetURL, nil)

	client := &http.Client{}
	resp, _ := client.Do(req)
	defer resp.Body.Close()
	body, _ := io.ReadAll(resp.Body)
	fmt.Println(string(body))
}

require "net/http"
require "json"

uri = URI("https://api.weatherapi.com/v1/forecast.json")
uri.query = URI.encode_www_form({
  "q" => "New York",
  "key" => "YOUR_KEY",
  "days" => "3"
})

http = Net::HTTP.new(uri.host, uri.port)
http.use_ssl = uri.scheme == "https"

req = Net::HTTP::Get.new(uri)

res = http.request(req)
puts JSON.parse(res.body)

<?php
$url = "https://api.weatherapi.com/v1/forecast.json?" . http_build_query([
    "q" => "New York",
    "key" => "YOUR_KEY",
    "days" => "3"
]);
$opts = ["http" => [
    "method" => "GET",
]];
$ctx = stream_context_create($opts);
$res = file_get_contents($url, false, $ctx);
print_r(json_decode($res, true));

Postman Setup Guide

Get Postman ↗

Get a free API key at weatherapi.com
Pass key=YOUR_KEY on all requests
Location can be city name, lat/lon, zip code, or IP address
Current: GET /current.json?key=KEY&q=Tokyo
Forecast: GET /forecast.json?key=KEY&q=Paris&days=7
History: GET /history.json?key=KEY&q=Rome&dt=2026-01-01

What can you build with WeatherAPI?

WeatherAPI is a Science API. Developers commonly use science APIs for:

accessing research datasets and scientific literature
powering academic and R&D applications
running scientific calculations and simulations
visualising experimental and observational data
integrating with research and reference databases

API Key authentication. You'll receive a key after signing up. Send it with every request — in a header or query parameter. Keep it out of client-side code and never commit it to version control. WeatherAPI is free to use up to a usage limit, making it a low-risk choice to experiment with.

New to APIs? Read our beginner's guide

Open documentation ↗