A free weather API lets your website or app show a forecast, current conditions, or weather alerts without you ever typing them in. For a local business that can mean a “patio’s open” note, a snow-day banner, or a forecast next to an outdoor event.
There are a lot of them, and they aren’t all equal. Below I cover what to look for, then list every weather API on the public-apis list, sorted by what it’s good for.
This post is part of my free API series. The full list of categories is in the free API directory.
What a free weather API can do on a business site
- Show today’s forecast on a restaurant, golf course, or event page.
- Switch a banner automatically when snow or storms are coming.
- Warn about high UV or poor air quality for outdoor activities.
- Look back at past weather, for example to explain a slow week.
How to choose a free weather API
A few questions sort out most of the options:
- Is business use allowed? Some free weather services are for non-commercial use only. The public list notes this for Open-Meteo, for example. Read the terms before a business site depends on it.
- Do you need a key? No-key services are the fastest to try. Key-based services usually have clearer limits and support.
- Does it cover your area well? For US locations, the National Weather Service’s own API (“US Weather” below) is free, needs no key, and comes straight from the source.
- How often will you ask? A forecast changes a few times a day. Save the answer and reuse it for a while instead of asking on every page view. That keeps you well inside free limits and makes the page faster.
A simple way to add weather without slowing your site
The cleanest setup is to have your server fetch the forecast every hour or so, save it, and show the saved copy. Visitors get an instant page, you make very few requests, and if the weather service has a bad day your site keeps showing the last good forecast. Speed matters more than most people think, which I cover in why website speed matters.
Every weather API on the list
Each entry says whether you need a key. “No key needed” means you can try it right away. “Sign up for a key” means a free account first, and many of those have paid tiers once you grow. “Users connect their own account” means each person signs in with that service. The APIs come from the community-kept public-apis list, and the descriptions are mine. Services change, so check each one before you rely on it.
Good first stops
Well-known forecast services with a free way in. Start here for most business sites.
- AccuWeather: Forecasts, current conditions, and severe weather alerts from one of the best-known weather brands, looked up by city or location. A solid pick when you want familiar, detailed forecasts on a site. Sign up for a key.
- Meteorologisk Institutt: Norway’s national weather service shares its global forecasts for free. It covers the whole world, not just Norway, and asks that every request name your app so they know who is calling. No key; send your app name with each request.
- Micro Weather: Returns current conditions and forecasts for a location, plus some past weather, through one simple request. It’s part of a larger bundle of small developer APIs. Sign up for a key.
- Open-Meteo: Free worldwide forecasts, hour by hour and day by day, with no sign-up. The list marks it for non-commercial use, so check its terms before a business site depends on it. No key needed.
- OpenWeatherMap: One of the most widely used weather APIs: current weather, hourly and daily forecasts, and weather maps for any spot on Earth. Plenty of plugins and tutorials are built around it. Sign up for a key.
- Pirate Weather: A free forecast service built to work like the old Dark Sky API, which Apple shut down. Handy if you have older code written for Dark Sky and want it working again. No key needed.
- Tomorrow: Forecasts and live conditions from Tomorrow.io, including things like precipitation type, road risk, and air quality. It leans toward businesses that plan around the weather. Sign up for a key.
- US Weather: The National Weather Service’s own free API for the United States. It gives official forecasts, hourly data, and watches and warnings, and it needs no key. No key needed.
- Visual Crossing: Forecasts plus deep weather history, so you can ask what the weather was on a past date as easily as what it will be tomorrow. Good for reports that compare busy days with the weather. Sign up for a key.
- WeatherAPI: Current weather, forecasts, and history, plus extras like sunrise and sunset times, moon phase, and time zones in the same service. A friendly all-in-one choice. Sign up for a key.
- Weatherbit: Current conditions, hourly and daily forecasts, historical data, and severe weather alerts worldwide. Often used by apps that need both forecasts and history. Sign up for a key.
- Weatherstack: Real-time and historical weather for any location, returned in a lightweight format that’s easy to drop into a page. It’s run by the same company as several other APIs on this list. Sign up for a key.
Restaurants, patios, and outdoor plans
- OpenUV: Gives the UV index right now and forecast for any location, plus the sun’s position. Useful for pools, beaches, golf courses, and outdoor events that want a sun-safety note. Sign up for a key.
- Rainbow Weather: Minute-by-minute rain forecasts for the next few hours (called nowcasting), built from radar and satellite. Great for “rain starting in 20 minutes” style alerts. Sign up for a key.
- RainViewer: Live and recent weather radar images you can place on a map. Use it to show a moving radar loop on a page without running your own radar service. No key needed.
- Terrace Weather: Reads the forecast and gives a plain yes or no on whether a restaurant patio or terrace should be open. A neat fit for restaurants and bars with outdoor seating. No key needed.
Air quality and pollen
- AirNow: The US EPA’s air quality readings and forecasts by ZIP code or location. Good for outdoor businesses and events that want to post an air quality warning. Sign up for a key.
- AQICN: Air quality index readings for over a thousand cities around the world, from the World Air Quality Index project. Sign up for a key.
- BreezoMeter Pollen: Daily pollen forecasts by type (trees, grass, weeds) for a specific location. Useful for health, allergy, and outdoor activity apps. Sign up for a key.
- IQAir: Air quality and weather readings from IQAir’s network of monitoring stations, by city or coordinates. Sign up for a key.
- OpenAQ: An open collection of air quality measurements from government and research monitors around the world. Good for research, maps, and dashboards. Sign up for a key.
History, storms, and totals
Handy for looking back: storm reports, snowfall, and past conditions.
- Hail History: Looks up past hail events at any US address, by year, using NOAA radar detections. Roofers, insurance agents, and home buyers use this kind of data. No key needed.
- NASA POWER: Solar and weather data from NASA, built for energy and farming use: sunlight, temperature, rainfall, and wind for any spot. Useful for solar panel estimates and crop planning. No key needed.
- Oikolab: Over 70 years of hourly past weather, plus forecasts, drawn from major weather agencies. Good for long-term trend analysis. Sign up for a key.
- WeatherTotals: Measured snow, rain, and hail totals by US state and city. Handy for “how much snow did we get” pages and seasonal reports. No key needed.
Forecasts from specific countries
National weather services and regional providers. Useful if you have customers or locations abroad.
- Aemet: Spain’s national weather agency’s open data: forecasts, observations, and warnings for Spain. Sign up for a key.
- ColorfulClouds: Weather and minute-by-minute rain forecasts from a Chinese provider, strongest in China. Sign up for a key.
- Euskalmet: Weather data from the Basque Country’s regional weather service in northern Spain. Sign up for a key.
- HG Weather: Weather forecasts for cities in Brazil, with responses in Portuguese. Sign up for a key.
- Hong Kong Obervatory: Hong Kong’s official weather office shares forecasts, warnings, earthquake reports, and climate data. No key needed.
- IPMA: Portugal’s weather and climate institute shares forecasts, warnings, and observations for Portugal. No key needed.
- KNMI: The Netherlands’ weather institute shares Dutch weather, radar, and climate data sets. Sign up for a key.
- Météo-France: France’s national weather service: forecasts, observations, and weather alerts for France and its territories. Sign up for a key.
- QWeather: Location-based forecasts, air quality, and weather alerts from a Chinese provider with worldwide coverage. Sign up for a key.
- Yandex.Weather: Forecasts and current conditions from Yandex, strongest in Russia and nearby countries. Sign up for a key.
Other weather services
Hobby, aviation, marine, and developer-friendly options.
- 7Timer!: Free forecasts designed for astronomy, telling stargazers about cloud cover, seeing, and transparency, with standard weather too. No key needed.
- APIXU: An older weather API whose service moved to Weatherstack. The old address may no longer work, so use Weatherstack instead. Sign up for a key.
- AviationWeather: NOAA’s aviation weather: airport observations (METARs), terminal forecasts (TAFs), and flight hazards. Built for pilots and flight-planning tools. No key needed.
- Foreca: Forecasts and observations from Foreca, a Finnish weather company that supplies weather to many media sites. Users connect their own account.
- Meltema: Point forecasts from several major global weather models side by side, with no key. Useful when you want to compare what different models predict. No key needed.
- ODWeather: Weather readings and weather webcams, focused on coastal and marine spots. No key needed.
- Open-Meteo Ensemble: Runs of many forecast models at once, so you can see how confident a forecast is. More for weather enthusiasts and planners than for a simple website widget. No key needed.
- openSenseMap: Readings from thousands of personal, citizen-run weather and environment sensors called senseBoxes. No key needed.
- Storm Glass: Marine weather worldwide: waves, swell, tides, water temperature, and wind. Made for boating, fishing, and surf apps. Sign up for a key.
- weather-api: A tiny open-source weather service that returns the current weather for a city. Mostly useful for learning and quick tests. No key needed.
- World Time & Weather: Current weather together with local time, UTC offset, and daylight saving rules for about 400 major cities, served as simple files. No key needed.
- wttr.in: Weather you can check from a command line, with a JSON option for code. Popular with developers for quick scripts. No key needed.
Questions I hear a lot
What is the best free weather API?
For US businesses, the National Weather Service API is hard to beat: free, no key, and official. If you need worldwide coverage or extra features, OpenWeatherMap, WeatherAPI, and Visual Crossing are common choices with free tiers.
Is the National Weather Service API really free?
Yes. It’s a public US government service. It asks you to identify your app when you make requests, and it only covers the United States.
Can I use Open-Meteo for a business website?
The public list describes Open-Meteo as free for non-commercial use. Check its current terms and pricing page before using it on a business site.
How often should my site check the weather?
Every 30 to 60 minutes is plenty for most sites. Save the result and show that saved copy to visitors.
If you’d like a hand
Picking an API and wiring it into a website or small app safely is part of my apps and platforms work. If you want weather or other live info on your site, send me a note with what you have in mind.