Climate averages 1991–2020
Hermosillo weather
by month.
See how the year changes. June has the highest average daily maximum; May has the lowest average monthly rainfall.
Pleasant-weather months by our simple rule: JanuaryFebruaryMarchNovemberDecember
Long-term climate patterns, not a forecast for a particular trip.
Across the year Hermosillo averages a daytime high of 31.6°C and a nighttime low of 17.3°C, with about 232 mm of rain on roughly 36 days. June is the warmest month (average high 39.1°C) and December the coolest (23.1°C). September is the wettest month with 52 mm; May is the driest with under 1 mm.
Months with pleasant weather by a simple rule (average high between 18°C and 29°C, average low of at least 5°C and at most 8 rain days): January, February, March, November and December. This looks at temperature and rain only, not humidity, wind, sea temperature or crowds.
The annual picture
A year in Hermosillo
Monthly rainfall
Average total · mmAverages from hourly ERA5 reanalysis data. Actual weather varies from year to year. How these numbers are calculated
Every month, side by side
Hermosillo climate table
| Month | Average highHigh / low | Average low | Rainfall mm/month | Rain days ≥1 mm/day | Daylight hours/dayDaylight h/day |
|---|---|---|---|---|---|
| January | 23.8°C9.4°C | 9.4°C | 12 | 1.6 | 10.511 h |
| February | 25.0°C10.3°C | 10.3°C | 15 | 2.0 | 11.111 h |
| March | 28.5°C12.3°C | 12.3°C | 6.5 | 0.8 | 12.012 h |
| April | 31.7°C14.9°C | 14.9°C | 1.4 | 0.4 | 12.813 h |
| May | 35.2°C18.1°C | 18.1°C | 0.4 | 0.1 | 13.614 h |
| June | 39.1°C23.3°C | 23.3°C | 3.3 | 1.1 | 14.014 h |
| July | 38.3°C26.6°C | 26.6°C | 40 | 7.6 | 13.814 h |
| August | 37.6°C26.6°C | 26.6°C | 51 | 9.8 | 13.213 h |
| September | 36.0°C24.5°C | 24.5°C | 52 | 7.1 | 12.412 h |
| October | 33.2°C19.1°C | 19.1°C | 19 | 2.1 | 11.511 h |
| November | 27.9°C13.5°C | 13.5°C | 13 | 1.5 | 10.711 h |
| December | 23.1°C9.4°C | 9.4°C | 19 | 1.9 | 10.310 h |
Rainfall is the average of the 30 separate monthly totals. A rain day is a local calendar day with at least 1 mm of precipitation. Daylight is the calculated sunrise-to-sunset length, not measured sunshine.
Compare places
Nearby cities
- Heroica GuaymasMexico · 130 kmHigh 28.1°C · Low 20.2°C · 164 mm rain a year
- Ciudad ObregónMexico · 205 kmHigh 32.4°C · Low 18.2°C · 329 mm rain a year
- NogalesMexico · 247 kmHigh 25.0°C · Low 10.7°C · 433 mm rain a year
- NavojoaMexico · 270 kmHigh 32.6°C · Low 18.4°C · 371 mm rain a year
- Agua PrietaMexico · 284 kmHigh 25.7°C · Low 11.7°C · 278 mm rain a year
- TucsonUnited States · 348 kmHigh 27.8°C · Low 14.0°C · 238 mm rain a year
- CuauhtémocMexico · 407 kmHigh 21.3°C · Low 8.0°C · 421 mm rain a year
- Los MochisMexico · 415 kmHigh 31.1°C · Low 19.7°C · 333 mm rain a year
Read the numbers correctly
Climate, not a promise.
These patterns help compare months. They cannot tell you the weather on a specific day of your trip.
Sources, method and limitsWhat do the high and low temperatures mean?
We average the daily maximum and daily minimum for each calendar month over 1991–2020. They are not record extremes, a forecast range or temperatures at a fixed time of day.
How is a rain day counted?
A local calendar day (standard time, UTC-7, no daylight saving) with at least 1 mm of total precipitation counts as one rain day. We count these for each year and month, then average across 30 years. The average does not predict which days will be wet.
Where do the numbers come from?
ERA5-Land (temperature) and ERA5 (precipitation) reanalysis from the Copernicus Climate Change Service, read from the Open-Meteo open-data archive. Temperature comes from the 0.1° model cell at 29.10°, -111.00° (4 km from the city centre), adjusted up by 0.2°C for the difference between the city's elevation (202 m) and the cell's (234 m). Rain comes from the 0.25° cell at 29.00°, -111.00°. These are model estimates, not weather-station readings; coast, hills and city streets can differ.
Does this page show sunshine, humidity or sea temperature?
No. The data used here contain air temperature and precipitation only. Daylight hours are calculated from the city's latitude (sunrise to sunset), not measured sunshine.