Three Castles climate — normals and trends
Three Castles (Iran) has a cold desert climate (BWk) under the Köppen-Geiger classification. Its mean annual temperature is 15.3 °C and it receives 114 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 (29.1 °C on average) and the coldest is January (0.7 °C). Rainfall peaks in March.
Three Castles averages 93 frost days, 121 hot days (≥ 30 °C) and 28 rainy days per year.
Three Castles has warmed by +2.6 °C between 1940 and 2025, or +0.31 °C per decade. This trend is statistically significant.
The number of frost days there went from about 110 to 76 per year over the period.
The hottest day of the period reached 42.6 °C (on 3 July 2025) and the coldest -23.7 °C (on 21 December 1964).
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
Three CastlesIsfahan
- coords
- 32.69°, 51.54°
- period
- 1940–2025 · 86 yrs
Mean daily temperature
15.3°C
Average daily high
22.5°C
Average daily low
8.1°C
Annual rainfall
114mm
Sunshine / day
11.1h
Mean relative humidity
37%
Average peak wind
14.6km/h
Seasonal range
28.4°C
Frost days (< 0 °C)
93 d/yr
Hot days (≥ 30 °C)
121 d/yr
Rainy days (≥ 1 mm)
28 d/yr
Annual snowfall
16.2 cm
Average feels-like high
19.6 °C
Average feels-like low
4.7 °C
Average peak gust
31.9 km/h
Tropical nights (≥ 20 °C)
41 d/yr
Solar radiation
21.2 MJ/m²
Has the climate changed?
One stripe per year, 1940 to 2025
+2.6 °C
since 1940
+0.3 °C per decade · r² = 0.51 · 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
3 July 2025
Coldest day
-23.7 °C
21 December 1964
Wettest day
34 mm
8 April 1961
Windiest day
45.3 km/h
19 October 1984
Strongest gust
108.0 km/h
26 March 2003
Hottest feels-like
40.9 °C
27 July 2024
Coldest feels-like
-28.7 °C
21 December 1964
Snowiest day
15.1 cm
29 January 1972
Sunniest day
13.1 h
16 June 1940
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 | 9.5 °C | +2.0 °C | 14 mm | -2 mm |
| Feb | 12.3 °C | +1.5 °C | 5 mm | -10 mm |
| Mar | 18.5 °C | +2.4 °C | 26 mm | +6 mm |
| Apr | 26.8 °C | +4.8 °C | 9 mm | -8 mm |
| May | 33.0 °C | +5.1 °C | 3 mm | -8 mm |
| Jun | 35.9 °C | +2.0 °C | 1 mm | -1 mm |
| Jul | 38.2 °C | +2.0 °C | 0 mm | -0 mm |
| Aug | 36.6 °C | +1.8 °C | 0 mm | -0 mm |
| Sep | 33.5 °C | +2.4 °C | 0 mm | -0 mm |
| Oct | 28.1 °C | +3.9 °C | 0 mm | -4 mm |
| Nov | 19.7 °C | +4.0 °C | 0 mm | -14 mm |
| Dec | 9.8 °C | +0.4 °C | 58 mm | +43 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 Three Castles?
Three Castles has a cold desert climate (Köppen BWk). Over 1940-2025, the average annual temperature is 15.3 °C and it receives 114 mm of precipitation per year.
What is the hottest day ever recorded in Three Castles?
The hottest day measured in Three Castles between 1940 and 2025 was 3 July 2025, reaching 42.6 °C.
What is the coldest day in Three Castles?
The coldest day measured in Three Castles between 1940 and 2025 was 21 December 1964, at -23.7 °C.
Does it snow in Three Castles?
Yes. Three Castles gets on average 16.2 cm of snow per year and has around 93 frost days.
Has the climate of Three Castles warmed?
Yes: Three Castles warmed by +2.6 °C between 1940 and 2025, a statistically significant trend.
What is the wettest day in Three Castles?
The wettest day measured in Three Castles between 1940 and 2025 was 8 April 1961, with 34 mm of rain in 24 hours.
What was the windiest day in Three Castles?
The windiest day measured in Three Castles between 1940 and 2025 was 19 October 1984, with winds reaching 45.3 km/h.
What is the warmest month in Three Castles?
The warmest month in Three Castles is July (29.1 °C on average); the coldest is January (0.7 °C).
How much does it rain in Three Castles?
Three Castles receives on average 114 mm of precipitation per year, spread over about 28 rainy days.
Is it sunny in Three Castles?
Three Castles gets on average 11.1 hours of sunshine per day, roughly 4,052 hours per year over 1940-2025.
What is the biggest single-day snowfall in Three Castles?
The heaviest 24-hour snowfall measured in Three Castles between 1940 and 2025 was 29 January 1972, with 15.1 cm.
Are there tropical nights in Three Castles?
Yes: Three Castles has on average 41 tropical nights per year (temperature staying above 20 °C), over 1940-2025.
What was the most extreme apparent temperature in Three Castles?
In Three Castles, between 1940 and 2025, the highest apparent temperature reached 40.9 °C on 27 July 2024, and the lowest was -28.7 °C on 21 December 1964.
Compare Three Castles with another city
Pick a second city: its normals will be set against these, indicator by indicator.
Nearby cities
The climate around Three Castles