Mértola climate — normals and trends
Mértola (Portugal) has a hot-summer mediterranean climate (Csa) under the Köppen-Geiger classification. Its mean annual temperature is 16.9 °C and it receives 413 mm of precipitation per year.
These figures are normals computed over 86 complete calendar years, from 1940 to 2025, using ERA5 reanalysis data from the Copernicus programme.
The warmest month is July (24.9 °C on average) and the coldest is January (9.7 °C). Rainfall peaks in December.
Mértola averages 3 frost days, 75 hot days (≥ 30 °C) and 64 rainy days per year.
Mértola has warmed by +1.0 °C between 1940 and 2025, or +0.11 °C per decade. This trend is statistically significant.
The number of frost days there went from about 5 to 1 per year over the period.
The hottest day of the period reached 44.7 °C (on 1 August 2003) and the coldest -4.1 °C (on 12 February 1956).
Data from ERA5 reanalysis (Copernicus Climate Change Service), redistributed under a CC-BY 4.0 licence. Normals are recomputed whenever the archive is updated.
Climate normals · ERA5
MértolaBeja District
- coords
- 37.64°, -7.66°
- period
- 1940–2025 · 86 yrs
Mean daily temperature
16.9°C
Average daily high
22.7°C
Average daily low
11.6°C
Annual rainfall
413mm
Sunshine / day
10.4h
Mean relative humidity
67%
Average peak wind
15.7km/h
Seasonal range
15.2°C
Frost days (< 0 °C)
3 d/yr
Hot days (≥ 30 °C)
75 d/yr
Rainy days (≥ 1 mm)
64 d/yr
Annual snowfall
0.1 cm
Average feels-like high
21.7 °C
Average feels-like low
10.1 °C
Average peak gust
33.2 km/h
Tropical nights (≥ 20 °C)
15 d/yr
Solar radiation
17.7 MJ/m²
Has the climate changed?
One stripe per year, 1940 to 2025
+1.0 °C
since 1940
+0.1 °C per decade · r² = 0.20 · p = < 0.001
Trend fitted by linear regression (ordinary least squares) on annual means. A trend is shown only when it is statistically significant (p < 0.05).
A climograph overlays rainfall (bars) and temperature (line): the standard reading in climatology, where you can see at a glance whether the warm season is also the dry one.
Records for the period
Hottest day
44.7 °C
1 August 2003
Coldest day
-4.1 °C
12 February 1956
Wettest day
71 mm
23 September 2021
Windiest day
56.3 km/h
15 February 1941
Strongest gust
108.4 km/h
13 January 1969
Hottest feels-like
46.0 °C
1 August 2003
Coldest feels-like
-8.5 °C
12 February 1956
Snowiest day
2.5 cm
2 February 1954
Sunniest day
14.6 h
20 June 2025
Normals computed over complete calendar years 1940–2025.
A specific year
Pick a year and see how it compares to normal — warmer, drier or more extreme than usual?
Across the whole year
Month by month
| High | vs. normal | Precipitation | vs. normal | |
|---|---|---|---|---|
| Jan | 16.0 °C | +1.7 °C | 93 mm | +44 mm |
| Feb | 17.2 °C | +1.6 °C | 28 mm | -17 mm |
| Mar | 17.1 °C | -1.2 °C | 147 mm | +97 mm |
| Apr | 21.2 °C | +0.7 °C | 64 mm | +21 mm |
| May | 26.2 °C | +1.9 °C | 11 mm | -18 mm |
| Jun | 33.1 °C | +4.2 °C | 2 mm | -11 mm |
| Jul | 33.8 °C | +1.4 °C | 0 mm | -2 mm |
| Aug | 34.6 °C | +2.3 °C | 0 mm | -3 mm |
| Sep | 30.1 °C | +1.4 °C | 2 mm | -18 mm |
| Oct | 27.2 °C | +3.6 °C | 33 mm | -19 mm |
| Nov | 18.6 °C | +0.5 °C | 61 mm | +8 mm |
| Dec | 14.8 °C | -0.1 °C | 108 mm | +52 mm |
The year's extremes
What was the weather like that day?
Your birthday, a wedding, a memorable trip: discover the actual weather for any date since 1940.
Frequently asked questions
What is the climate of Mértola?
Mértola has a hot-summer mediterranean climate (Köppen Csa). Over 1940-2025, the average annual temperature is 16.9 °C and it receives 413 mm of precipitation per year.
What is the hottest day ever recorded in Mértola?
The hottest day measured in Mértola between 1940 and 2025 was 1 August 2003, reaching 44.7 °C.
What is the coldest day in Mértola?
The coldest day measured in Mértola between 1940 and 2025 was 12 February 1956, at -4.1 °C.
Does it snow in Mértola?
Almost never: Mértola sees virtually no snow, with about 3 frost days per year.
Has the climate of Mértola warmed?
Yes: Mértola warmed by +1.0 °C between 1940 and 2025, a statistically significant trend.
What is the wettest day in Mértola?
The wettest day measured in Mértola between 1940 and 2025 was 23 September 2021, with 71 mm of rain in 24 hours.
What was the windiest day in Mértola?
The windiest day measured in Mértola between 1940 and 2025 was 15 February 1941, with winds reaching 56.3 km/h.
What is the warmest month in Mértola?
The warmest month in Mértola is July (24.9 °C on average); the coldest is January (9.7 °C).
How much does it rain in Mértola?
Mértola receives on average 413 mm of precipitation per year, spread over about 64 rainy days.
Is it sunny in Mértola?
Mértola gets on average 10.4 hours of sunshine per day, roughly 3,796 hours per year over 1940-2025.
What is the biggest single-day snowfall in Mértola?
The heaviest 24-hour snowfall measured in Mértola between 1940 and 2025 was 2 February 1954, with 2.5 cm.
Are there tropical nights in Mértola?
Yes: Mértola has on average 15 tropical nights per year (temperature staying above 20 °C), over 1940-2025.
What was the most extreme apparent temperature in Mértola?
In Mértola, between 1940 and 2025, the highest apparent temperature reached 46.0 °C on 1 August 2003, and the lowest was -8.5 °C on 12 February 1956.
Compare Mértola with another city
Pick a second city: its normals will be set against these, indicator by indicator.
Nearby cities
The climate around Mértola