Show HN: Weather API for non-commercial use (open-meteo.com)

• ultra-weather

  15 70 1.5 Svelte

  UltraWeather gives user-friendly, actionable weather forecasts.

I've investigated and tried several (free) weather API's for my web app: https://uw.leftium.com.

Open-Meteo looks pretty good! The only thing that seems to be missing for me is precipitation probability. The weathercode is sort of a proxy for this... I'm also interested in sunrise/sunset times; direct_radiation is kind of a proxy for this.

Kudos for providing optional historical data with the same API call for the forecast. Many weather API's don't provide historical data, and even if they do, it requires extra calls. My weather app charts the previous two days of weather with the forecast for comparison. I feel this gives a more intuitive sense of the weather vs. raw numbers because weather is very relative. ("Warm" vs "cool" depends on your location and season.)

In addition, I am in the process of adding AQI forecasts, which requires even more network calls. It seems like this is on the roadmap for open-meteo. I was surprised to find there are so many different standards for AQI. Curious to know which one you plan to use.

One possible suggestion for optimizing the output format: sending seconds since the Unix epoch would save a few bytes per timestamp. I'm not sure if this would make any noticeable difference with gzip compression. The current datetime format is much more human-readable and may save a conversion before displaying.

These were the best (free) weather API's I could find. It's interesting how the three different weather forecasts can disagree so much:

- https://openweathermap.org/api

- https://www.visualcrossing.com/weather-api

- https://darksky.net/dev (deprecated)

When I find the time, I will add open-meteo as to my app! I'll probably have more feedback then.

• open-meteo

  45 1,922 9.7 Swift

  Free Weather Forecast API for non-commercial use

  

Thanks for your suggestions!

I will add precipitation probability as soon as I include 14-day ensemble weather models. Deterministic whether models usually do not offer this directly.

I also really like the 2 days historical access :) At some point I would like to add more, but the storage requirements skyrocket quickly. Not only in space, but also disk IO to perform in-place updates.

For air quality data I want to add first all variables individually. AQI can be calculated afterwards on-the-fly. Some AQI indices require data from the previous hours, but it should work well with 2 days past data. For sure I will directly integrate the European and US AQI.

I considered unix-timestamp instead of ISO9601 string timestamps. Working with unix-timestamps is a bit trickier if you also want to use timezones. For the start, i settled with ISO8601 timestamps. I might consider adding unix timestamps as an `&timeformat=unix` parameter to the API. Regarding saving bytes in the output: I would like to implement protobuf as a format and also use it to build some SDKs. Especially with large floating point arrays, this saves a lot of parsing time and preserves precision.

All your suggestions are now kept in the Open-Meteo backlog https://github.com/open-meteo/open-meteo/issues

• WorkOS

  workos.com sponsored

  The modern identity platform for B2B SaaS. The APIs are flexible and easy-to-use, supporting authentication, user identity, and complex enterprise features like SSO and SCIM provisioning.

  

• clearmycal

  1 0 2.5 Python

  An alerting system to let you know if the weather is going to be "relatively great" in the next 7 days

Darksky did not offer this feature I don't think.

For my use the accuracy is not critical.

[1] https://github.com/mattarderne/clearmycal

• h3

  21 4,593 7.2 C

  Hexagonal hierarchical geospatial indexing system

  

Looks really awesome! Very quick responses.

I would be interested in seeing the implementation of the service, interesting choice going with Swift. I'm guessing your using something like Vapor for hosting the API?

How are the files designed? I'm guessing you have some cheap way of mapping (lat, long) into a file location? Maybe just by truncating the coordinates to your precision and mapping them onto the file? Using some fancy-pants Uber Hexagons[0]. How is the forecast delivered?

Hmm! Many questions :-). I've been thinking lately of similar (but not for weather) "geographical" API's, and how to store/query data cheaply, so this interested me :-)

[0]: https://github.com/uber/h3

• umbrella-hook

  1 3 0.0 C++

  An umbrella hook that glows blue when rain is forecast for the area.

Thank you! I found you some time ago in a Github list of free APIs; you made it possible for me to design a "smart" umbrella hook https://github.com/jareklupinski/umbrella-hook

I'm updating the code now to parse your weathercode for predicting umbrella necessity, and has been an accurate meter in my area for the past week.

• yr-weather-symbols

  1 125 6.5 TypeScript

  Weather symbols for yr.no

  

• local-reverse-geocoder

  1 186 6.0 JavaScript

  Local reverse geocoder for Node.js based on GeoNames data

I recently contributed to https://github.com/tomayac/local-reverse-geocoder - while it's a reverse geocoder, it a ready template for downloading OSM cities data and searching through it.

• InfluxDB

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