San Juan weather
Loading live data…Latest for San Juan: NWS (National Blend (NBM)): 71° Clear · American (NOAA GFS): 67° Clear · European (ECMWF): 73° Clear.
CheckWeather.io on iPhoneFree. No ads, no account.San Juan weather alerts and warnings
active National Weather Service watches, warnings and advisoriesChecking the National Weather Service for active alerts covering San Juan…
San Juan weather in numbers
measured normals and 10 years of recorded weatherSan Juan swings 43°F across the year, from 96°F highs in August to 53°F lows in January, and September is usually the wettest month in a year that brings about 23 in of precipitation. Over 10 years of recorded weather it averages 296 days a year at 77°F or above, 216 of them at 86°F or above, 1 frost night, and rain on 92 days.
Day counts are from the ERA5 reanalysis for San Juan’s grid square, 2016 to 2025, counted the same way for every city so the numbers compare. A reanalysis square is an area, not a weather station, so it is good for counting days and not for a single day’s record.
The weather map: all three models at once
NWS, American, European side by side around San Juan and nearby towns.Live rain radar →San Juan hourly forecast: next 14 hours
consensus of the three modelsRain in the next 24 hours, model by model
each model's own hourly precipitation, side by sideLoading the three models…
San Juan 10-day forecast, out to 14 days
where the models agree, and where they splitSan Juan, Texas (TX) is at its warmest in Aug (average highs near 96°F) and coldest in Jan (lows around 53°F), with roughly 23 in of precipitation across the year. Below, compare what NWS, American, European forecast for San Juan right now, and see exactly where they disagree.
We grade every model against the weather that actually happened, so you can see which forecast model is most accurate in United States before you trust any single number.
San Juan climate by month
average daytime high and overnight low across a typical year (1991-2020)Source: 1991-2020 averages, ERA5 for this place adjusted with NASA POWER.
How the weather around San Juan has changed since 1995
San Juan sits in the same roughly 50 km square of NASA's reanalysis as McAllen. That square shows no clear change in temperature between 1995-2004 and 2015-2024. See the full 30-year picture on the McAllen page.
Which forecast is most accurate in San Juan?
CheckWeather Score, graded against the weather that actually happened
The CheckWeather Score blends temperature, wind and rain accuracy, each measured against ERA5 (the recorded weather) over the last 30 days across 1999 cities. Lower error means a higher score. See which forecast model is most accurate in United States, how we measure forecast accuracy, or which model each weather app uses.
What do you think of the forecasts?
your vote countsThe accuracy above is the measured record. This is your opinion: which forecast service do you trust most in United States? Give each 1 to 5 stars.
One vote per service. Anonymous: we store no personal data, only a one-way hash of your connection for a day to stop double votes.