Hermanus weather by month
Hermanus runs from about 11°C in July to 21°C in January, with July the wettest month at 220 mm.
warmest month
January
21°C
coolest month
July
11°C
wettest month
July
220 mm
worst air month
August
9 µg/m³
The whole year, month by month.
| Month | Avg temp | Rain | Sun | PM2.5 |
|---|---|---|---|---|
| January | 21°C | 13 mm | 373 h | 8 |
| February | 21°C | 38 mm | 359 h | 7 |
| March | 19°C | 38 mm | 307 h | 6 |
| April | 16°C | 73 mm | 277 h | 6 |
| May | 15°C | 22 mm | 268 h | 7 |
| June | 14°C | 128 mm | 242 h | 7 |
| July | 11°C | 220 mm | 234 h | 7 |
| August | 12°C | 85 mm | 274 h | 9 |
| September | 13°C | 44 mm | 313 h | 8 |
| October | 16°C | 35 mm | 362 h | 8 |
| November | 18°C | 33 mm | 356 h | 7 |
| December | 19°C | 22 mm | 393 h | 7 |
About 3,758 hours of sun a year. Roughly 75 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 2026-05-25. Full method, licences and the list of sources we rejected are on the methodology page.