Modelled averages 2001–2025
Lisbon weather
in May.
Average daily highs of 19.9°C and lows of 14.3°C. About 30.8 mm of rain across 4.5 rain days in a typical May.
Long-term climate patterns — not a forecast for a particular trip.
The annual picture
May in context
Monthly rainfall
Average total · mmAverages from daily ERA5 reanalysis. Actual weather varies from year to year. How these numbers are calculated
Every month, side by side
Lisbon climate table
| Month | Average highHigh / low | Average low | Rainfall mm/month | Rain days ≥1 mm/day |
|---|---|---|---|---|
| January | 14.1°C9.9°C | 9.9°C | 60.6 | 8.7 |
| February | 14.7°C10.0°C | 10.0°C | 55.9 | 8.0 |
| March | 16.0°C11.1°C | 11.1°C | 65.9 | 9.5 |
| April | 17.5°C12.5°C | 12.5°C | 51.3 | 8.3 |
| May, selected | 19.9°C14.3°C | 14.3°C | 30.8 | 4.5 |
| June | 22.3°C16.4°C | 16.4°C | 10.6 | 2.4 |
| July | 23.8°C17.5°C | 17.5°C | 1.8 | 0.6 |
| August | 24.5°C18.0°C | 18.0°C | 2.7 | 0.7 |
| September | 23.4°C17.5°C | 17.5°C | 30.5 | 3.9 |
| October | 21.0°C16.1°C | 16.1°C | 77.4 | 9.4 |
| November | 17.0°C12.7°C | 12.7°C | 83.3 | 10.0 |
| December | 14.8°C10.7°C | 10.7°C | 74.6 | 8.8 |
Rainfall is the average of the 25 separate monthly totals. Rain days are the mean number of UTC days with at least 1 mm of precipitation.
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.
Open the source dataWhat do the high and low temperatures mean?
We average the daily maximum and daily minimum for each calendar month over 2001–2025. They are not record extremes, a forecast range or temperatures at a fixed time of day.
How is a rain day counted?
A UTC day with at least 1 mm of total precipitation counts as one rain day. We count these separately for each year and month, then average across 25 years. The resulting average does not predict which days will be wet.
Where do the data come from?
Open-Meteo supplies ERA5 reanalysis: model-grid estimates, not a measurement at every address. This page uses 9131 daily records from 2001-01-01 to 2025-12-31. Retrieved 18 Oct 2026. Coastal, hilltop and neighbourhood conditions may differ.
Does this page show sunshine or sea temperature?
No. The selected dataset contains air temperature and precipitation. We do not infer sunshine hours, sea temperature or cloud cover from those values.
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