Houston weather by month
Houston runs from about 11°C in January to 29°C in August, with July the wettest month at 489 mm.
warmest month
August
29°C
coolest month
January
11°C
wettest month
July
489 mm
worst air month
August
14 µg/m³
The whole year, month by month.
| Month | Avg temp | Rain | Sun | PM2.5 |
|---|---|---|---|---|
| January | 11°C | 328 mm | 218 h | 12 |
| February | 16°C | 60 mm | 231 h | 13 |
| March | 18°C | 98 mm | 238 h | 9 |
| April | 22°C | 189 mm | 275 h | 9 |
| May | 26°C | 296 mm | 277 h | 14 |
| June | 28°C | 105 mm | 355 h | 14 |
| July | 27°C | 489 mm | 282 h | 12 |
| August | 29°C | 81 mm | 358 h | 14 |
| September | 26°C | 123 mm | 314 h | 14 |
| October | 24°C | 27 mm | 330 h | 11 |
| November | 20°C | 136 mm | 257 h | 9 |
| December | 16°C | 171 mm | 225 h | 10 |
About 3,360 hours of sun a year. Roughly 190 rainy days a year.
These are long-run climate normals, not a forecast. A given year can sit well outside them. PM2.5 is a global model: near the coast it counts sea salt as fine particulate and reads high against ground stations, sometimes by a factor of two. Use the shape of the year, not the absolute number.
where these numbers come from
- · Temperature, rainfall and sunshine: ECMWF ERA5 reanalysis climate normals via Open-Meteo (CC BY 4.0), fetched once and stored.
- · PM2.5: Copernicus CAMS reanalysis, monthly means. Modelled, not station readings; near coasts CAMS counts sea salt as PM2.5 and reads high.
Last reviewed 2026-05-23. Full method, licences and the list of sources we rejected are on the methodology page.