Riesi climate — normals and trends
Riesi (Italy) has a hot-summer mediterranean climate (Csa) under the Köppen-Geiger classification. Its mean annual temperature is 16.7 °C and it receives 484 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 (25.3 °C on average) and the coldest is January (9.1 °C). Rainfall peaks in October.
Riesi averages 5 frost days, 61 hot days (≥ 30 °C) and 70 rainy days per year.
Riesi has warmed by +1.8 °C between 1940 and 2025, or +0.21 °C per decade. This trend is statistically significant.
The number of frost days there went from about 9 to 1 per year over the period.
The hottest day of the period reached 42.6 °C (on 30 July 1945) and the coldest -5.8 °C (on 1 February 1962).
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
RiesiSicily
- coords
- 37.28°, 14.08°
- period
- 1940–2025 · 86 yrs
Mean daily temperature
16.7°C
Average daily high
22.0°C
Average daily low
11.8°C
Annual rainfall
484mm
Sunshine / day
10.7h
Mean relative humidity
71%
Average peak wind
17.2km/h
Seasonal range
16.2°C
Frost days (< 0 °C)
5 d/yr
Hot days (≥ 30 °C)
61 d/yr
Rainy days (≥ 1 mm)
70 d/yr
Annual snowfall
0.1 cm
Average feels-like high
21.4 °C
Average feels-like low
10.6 °C
Average peak gust
36.6 km/h
Tropical nights (≥ 20 °C)
29 d/yr
Solar radiation
17.8 MJ/m²
Has the climate changed?
One stripe per year, 1940 to 2025
+1.8 °C
since 1940
+0.2 °C per decade · r² = 0.48 · 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
42.6 °C
30 July 1945
Coldest day
-5.8 °C
1 February 1962
Wettest day
106 mm
9 December 1996
Windiest day
51.2 km/h
24 November 1991
Strongest gust
110.5 km/h
24 November 1991
Hottest feels-like
44.6 °C
9 August 1999
Coldest feels-like
-9.8 °C
1 February 1962
Snowiest day
0.9 cm
31 December 1941
Sunniest day
14.0 h
13 May 1940
Normals computed over complete calendar years 1940–2025.
A specific year
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Across the whole year
Month by month
| High | vs. normal | Precipitation | vs. normal | |
|---|---|---|---|---|
| Jan | 15.7 °C | +2.0 °C | 80 mm | +21 mm |
| Feb | 14.9 °C | +0.7 °C | 114 mm | +62 mm |
| Mar | 17.5 °C | +1.4 °C | 82 mm | +34 mm |
| Apr | 19.8 °C | +0.7 °C | 39 mm | +2 mm |
| May | 25.4 °C | +1.5 °C | 68 mm | +46 mm |
| Jun | 31.5 °C | +2.9 °C | 3 mm | -5 mm |
| Jul | 33.5 °C | +2.1 °C | 0 mm | -2 mm |
| Aug | 31.8 °C | +0.4 °C | 13 mm | +4 mm |
| Sep | 29.0 °C | +1.1 °C | 40 mm | +5 mm |
| Oct | 22.9 °C | -0.5 °C | 57 mm | -17 mm |
| Nov | 18.4 °C | -0.3 °C | 63 mm | -8 mm |
| Dec | 16.0 °C | +1.0 °C | 102 mm | +36 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 Riesi?
Riesi has a hot-summer mediterranean climate (Köppen Csa). Over 1940-2025, the average annual temperature is 16.7 °C and it receives 484 mm of precipitation per year.
What is the hottest day ever recorded in Riesi?
The hottest day measured in Riesi between 1940 and 2025 was 30 July 1945, reaching 42.6 °C.
What is the coldest day in Riesi?
The coldest day measured in Riesi between 1940 and 2025 was 1 February 1962, at -5.8 °C.
Does it snow in Riesi?
Almost never: Riesi sees virtually no snow, with about 5 frost days per year.
Has the climate of Riesi warmed?
Yes: Riesi warmed by +1.8 °C between 1940 and 2025, a statistically significant trend.
What is the wettest day in Riesi?
The wettest day measured in Riesi between 1940 and 2025 was 9 December 1996, with 106 mm of rain in 24 hours.
What was the windiest day in Riesi?
The windiest day measured in Riesi between 1940 and 2025 was 24 November 1991, with winds reaching 51.2 km/h.
What is the warmest month in Riesi?
The warmest month in Riesi is July (25.3 °C on average); the coldest is January (9.1 °C).
How much does it rain in Riesi?
Riesi receives on average 484 mm of precipitation per year, spread over about 70 rainy days.
Is it sunny in Riesi?
Riesi gets on average 10.7 hours of sunshine per day, roughly 3,905 hours per year over 1940-2025.
What is the biggest single-day snowfall in Riesi?
The heaviest 24-hour snowfall measured in Riesi between 1940 and 2025 was 31 December 1941, with 0.9 cm.
Are there tropical nights in Riesi?
Yes: Riesi has on average 29 tropical nights per year (temperature staying above 20 °C), over 1940-2025.
What was the most extreme apparent temperature in Riesi?
In Riesi, between 1940 and 2025, the highest apparent temperature reached 44.6 °C on 9 August 1999, and the lowest was -9.8 °C on 1 February 1962.
Compare Riesi with another city
Pick a second city: its normals will be set against these, indicator by indicator.
Nearby cities
The climate around Riesi