WEATHER · CLIMATE NORMALS · 1991–2020
Lisbon Climate — Averages by Month
What the weather in Lisbon, PTaverages across a standard 30-year period. Each month's figure is the 1991–2020 mean temperature and total rainfall from the ERA5 reanalysis — the long-run normal a place settles around, not a forecast for any particular day.
Month-by-month normals
| Month | Avg temperature | Avg rainfall |
|---|---|---|
| January | 11.7 °C · coldest | 73.5 mm |
| February | 12.0 °C | 55.1 mm |
| March | 13.6 °C | 57.3 mm |
| April | 14.7 °C | 56.4 mm |
| May | 16.7 °C | 46.7 mm |
| June | 19.0 °C | 12.7 mm |
| July | 20.4 °C | 3.6 mm |
| August | 20.9 °C · warmest | 5.8 mm |
| September | 20.0 °C | 31.5 mm |
| October | 17.9 °C | 82.2 mm |
| November | 14.6 °C | 87.8 mm · wettest |
| December | 12.6 °C | 83.3 mm |
How to read these numbers
These are reanalysis normals, not readings from a single weather station. They come from the ERA5 0.25° (~25 km) global reanalysis grid, sampled at the grid cell nearest Lisbon — centred at 38.75°N, 9.25°W. A reanalysis blends observations with a physics model onto an even grid, so a coastal or mountain city's cell can read a little cooler, warmer, wetter or drier than the city centre itself. The month-to-month shape — when it's hot, when it rains — is what these normals capture best.
“Normal” means the 1991–2020 average, the current World Meteorological Organization standard period. A normal is what a place tends toward over decades — any single day, month or year can and will depart from it.