Author Topic: Yahoo Weather Forecast Usage Enchancement  (Read 6645 times)


  • Administrator
  • LC Green Star Commander
  • *****
  • Posts: 183
Yahoo Weather Forecast Usage Enchancement
« on: March 07, 2019, 02:21:36 pm »
Yahoo has recently notified us (May 2021) that they will be terminating the Y! Weather API.   :(

Yahoo recently updated their weather API  (February 2019)  so we updated our weather requesting code to use their new feed.    In addition to using their new feed, we also enhanced the use of the weather forecasts provided by Yahoo for better control of irrigation.

The old Weather Underground (WU) feed was very powerful because it provided a forecast for PoP (Probability of Precipitation) and also provided local rain gauge information - if you subscribed to a station that had a rain gauge.  This allowed us to easily provide an option to block irrigation based on a PoP threshold that you set.   And it also allowed us to block irrigation if the rain gauge met a settable threshold, for both today and yesterday - because we saved the rain gauge data for one day.   So WU provided good data to block based on forecast and actual precipitation but this feed is no longer available.

We have noticed throughout the years a strong correlation between certain Yahoo forecast daily condition codes and high PoP values in the WU and other forecasts.   When the Yahoo daily condition code shows precipitation that corresponds to high PoP forecasts from other services, generally 50% or above.   So we have recently enhanced the Yahoo feed to use their daily condition codes to be able to block cycles if the codes for today and tomorrow contain precipitation.    This greatly enhances the use of Yahoo weather to reduce irrigation if rain is on the horizon.   

Please see our weather setup page for more info.

The Yahoo daily condition codes have worked extremely well in blocking cycles during this year's (2019) very wet winter and spring in northern California.
« Last Edit: May 29, 2021, 01:31:37 pm by Jim »