Dayton weather by month
Dayton runs from about -1°C in January to 24°C in July, with April the wettest month at 200 mm.
warmest month
July
24°C
coolest month
January
-1°C
wettest month
April
200 mm
worst air month
February
16 µg/m³
The whole year, month by month.
| Month | Avg temp | Rain | Sun | PM2.5 |
|---|---|---|---|---|
| January | -1°C | 120 mm | 125 h | 10 |
| February | 4°C | 45 mm | 243 h | 16 |
| March | 8°C | 82 mm | 239 h | 8 |
| April | 13°C | 200 mm | 288 h | 7 |
| May | 19°C | 138 mm | 330 h | 7 |
| June | 23°C | 112 mm | 364 h | 8 |
| July | 24°C | 67 mm | 380 h | 12 |
| August | 23°C | 75 mm | 369 h | 10 |
| September | 21°C | 107 mm | 291 h | 9 |
| October | 14°C | 13 mm | 311 h | 6 |
| November | 9°C | 103 mm | 169 h | 7 |
| December | 3°C | 113 mm | 149 h | 9 |
About 3,258 hours of sun a year. Roughly 118 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 2026-05-24. Full method, licences and the list of sources we rejected are on the methodology page.