Ad Dilam climate — normals and trends

Q: What is the climate of Ad Dilam?

Ad Dilam has a hot desert climate (Köppen BWh). Over 1940-2025, the average annual temperature is 26.2 °C and it receives 47 mm of precipitation per year.

Q: What is the hottest day ever recorded in Ad Dilam?

The hottest day measured in Ad Dilam between 1940 and 2025 was 17 July 2012, reaching 48.4 °C.

Q: What is the coldest day in Ad Dilam?

The coldest day measured in Ad Dilam between 1940 and 2025 was 29 January 1950, at -4.1 °C.

Q: Does it snow in Ad Dilam?

Almost never: Ad Dilam sees virtually no snow, with about 1 frost days per year.

Q: Has the climate of Ad Dilam warmed?

Yes: Ad Dilam warmed by +3.5 °C between 1940 and 2025, a statistically significant trend.

Q: What is the wettest day in Ad Dilam?

The wettest day measured in Ad Dilam between 1940 and 2025 was 26 April 2013, with 43 mm of rain in 24 hours.

Q: What was the windiest day in Ad Dilam?

The windiest day measured in Ad Dilam between 1940 and 2025 was 4 May 1952, with winds reaching 48.6 km/h.

Q: What is the warmest month in Ad Dilam?

The warmest month in Ad Dilam is July (36.1 °C on average); the coldest is January (14.3 °C).

Q: How much does it rain in Ad Dilam?

Ad Dilam receives on average 47 mm of precipitation per year, spread over about 10 rainy days.

Q: Is it sunny in Ad Dilam?

Ad Dilam gets on average 11.2 hours of sunshine per day, roughly 4,088 hours per year over 1940-2025.

Ad Dilam (Saudi Arabia) has a hot desert climate (BWh) under the Köppen-Geiger classification. Its mean annual temperature is 26.2 °C and it receives 47 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 (36.1 °C on average) and the coldest is January (14.3 °C). Rainfall peaks in March.

Ad Dilam averages 1 frost days, 230 hot days (≥ 30 °C) and 10 rainy days per year.

Ad Dilam has warmed by +3.5 °C between 1940 and 2025, or +0.41 °C per decade. This trend is statistically significant.

The number of frost days there went from about 2 to 0 per year over the period.

The hottest day of the period reached 48.4 °C (on 17 July 2012) and the coldest -4.1 °C (on 29 January 1950).

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

Ad DilamRiyadh Region

coords: 23.99°, 47.16°
period: 1940–2025 · 86 yrs

BWhHot desertWarmest monthJulyColdest monthJanuaryWettest monthMarchDriest monthJune

Mean daily temperature

26.2°C

Average daily high

33.3°C

Average daily low

18.8°C

Annual rainfall

47mm

Sunshine / day

11.2h

Mean relative humidity

27%

Average peak wind

18.3km/h

Seasonal range

21.8°C

Frost days (< 0 °C)

1 d/yr

Hot days (≥ 30 °C)

230 d/yr

Rainy days (≥ 1 mm)

10 d/yr

Annual snowfall

0.0 cm

Average feels-like high

30.9 °C

Average feels-like low

15.8 °C

Average peak gust

31.6 km/h

Tropical nights (≥ 20 °C)

179 d/yr

Solar radiation

22.7 MJ/m²

Has the climate changed?

One stripe per year, 1940 to 2025

+3.5 °C

since 1940

+0.4 °C per decade · r² = 0.76 · p = < 0.001

19402025

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

48.4 °C

17 July 2012

Coldest day

-4.1 °C

29 January 1950

Wettest day

43 mm

26 April 2013

Windiest day

48.6 km/h

4 May 1952

Strongest gust

76.7 km/h

4 May 1952

Hottest feels-like

48.4 °C

12 August 2003

Coldest feels-like

-10.5 °C

20 January 1964

Sunniest day

12.9 h

26 May 1949

Year	Hottest day	Coldest day	Annual mean	Rainfall	Hot days	Frost days
2025	46.9 °C16 June 2025	3.6 °C4 January 2025	27.6 °C	41 mm	232	0
2024	48.2 °C12 July 2024	4.8 °C16 December 2024	28.4 °C	13 mm	247	0
2023	47.7 °C18 July 2023	6.7 °C20 January 2023	28.2 °C	45 mm	241	0
2022	47.5 °C8 August 2022	4.1 °C22 January 2022	28.4 °C	37 mm	254	0
2021	47.2 °C12 July 2021	6.2 °C13 January 2021	28.6 °C	14 mm	250	0
2020	47.8 °C7 July 2020	1.8 °C13 February 2020	28.0 °C	14 mm	246	0
2019	47.3 °C29 June 2019	5.8 °C21 January 2019	28.0 °C	34 mm	228	0
2018	46.9 °C12 July 2018	4.6 °C22 January 2018	28.2 °C	23 mm	247	0
2017	47.8 °C3 July 2017	0.8 °C4 February 2017	28.0 °C	65 mm	237	0
2016	47.1 °C22 July 2016	2.5 °C31 January 2016	27.4 °C	57 mm	238	0
2015	46.6 °C17 July 2015	4.0 °C21 January 2015	28.2 °C	52 mm	247	0
2014	46.6 °C16 August 2014	3.8 °C8 January 2014	27.4 °C	35 mm	237	0
2013	46.8 °C18 July 2013	0.7 °C17 January 2013	26.7 °C	156 mm	236	0
2012	48.4 °C17 July 2012	0.3 °C22 January 2012	27.2 °C	51 mm	236	0
2011	48.0 °C15 July 2011	3.3 °C21 December 2011	27.1 °C	51 mm	241	0
2010	48.3 °C17 July 2010	3.0 °C8 February 2010	28.4 °C	19 mm	260	0
2009	46.7 °C10 August 2009	2.3 °C17 January 2009	27.8 °C	47 mm	246	0
2008	47.2 °C26 July 2008	-1.5 °C17 January 2008	27.3 °C	19 mm	243	1
2007	47.9 °C31 July 2007	0.5 °C4 January 2007	27.6 °C	30 mm	248	0
2006	46.7 °C27 July 2006	3.2 °C31 December 2006	27.4 °C	51 mm	242	0
2005	47.8 °C23 July 2005	1.7 °C13 January 2005	27.5 °C	45 mm	237	0
2004	46.1 °C26 July 2004	2.8 °C30 December 2004	27.3 °C	88 mm	250	0
2003	46.8 °C12 August 2003	3.4 °C18 January 2003	27.6 °C	46 mm	247	0
2002	47.8 °C23 July 2002	4.6 °C26 December 2002	27.3 °C	23 mm	236	0
2001	47.0 °C11 August 2001	1.9 °C30 January 2001	27.4 °C	18 mm	240	0
2000	47.3 °C8 July 2000	2.8 °C31 December 2000	27.3 °C	15 mm	228	0
1999	46.6 °C27 June 1999	5.2 °C6 January 1999	27.8 °C	13 mm	241	0
1998	47.9 °C7 August 1998	2.3 °C15 January 1998	27.6 °C	72 mm	237	0
1997	46.4 °C16 June 1997	4.5 °C27 January 1997	26.4 °C	86 mm	212	0
1996	46.9 °C13 July 1996	6.3 °C15 January 1996	26.8 °C	81 mm	222	0
1995	45.2 °C4 August 1995	4.6 °C3 January 1995	26.2 °C	168 mm	222	0
1994	46.8 °C3 June 1994	1.5 °C28 December 1994	26.9 °C	10 mm	235	0
1993	45.8 °C10 August 1993	1.0 °C18 January 1993	26.3 °C	43 mm	235	0
1992	46.3 °C16 June 1992	-2.4 °C7 January 1992	25.2 °C	86 mm	214	3
1991	46.6 °C27 June 1991	1.8 °C29 January 1991	26.4 °C	14 mm	237	0
1990	46.2 °C13 July 1990	0.3 °C30 December 1990	26.5 °C	14 mm	235	0
1989	46.5 °C6 July 1989	-1.7 °C7 January 1989	25.6 °C	48 mm	228	4
1988	46.6 °C17 June 1988	1.0 °C21 January 1988	26.3 °C	51 mm	236	0
1987	47.8 °C27 July 1987	1.5 °C13 January 1987	26.7 °C	43 mm	223	0
1986	45.9 °C27 July 1986	1.4 °C2 January 1986	25.8 °C	61 mm	219	0
1985	46.2 °C6 August 1985	3.4 °C7 December 1985	25.9 °C	34 mm	226	0
1984	44.4 °C24 July 1984	2.4 °C1 February 1984	25.7 °C	44 mm	215	0
1983	46.2 °C20 July 1983	1.7 °C22 January 1983	25.4 °C	97 mm	217	0
1982	45.7 °C19 July 1982	0.7 °C18 January 1982	25.3 °C	119 mm	216	0
1981	46.7 °C10 August 1981	2.4 °C16 January 1981	26.6 °C	17 mm	240	0
1980	46.5 °C22 July 1980	2.9 °C18 January 1980	26.6 °C	30 mm	249	0
1979	46.3 °C25 July 1979	3.7 °C3 December 1979	26.8 °C	31 mm	240	0
1978	46.3 °C23 July 1978	2.5 °C22 December 1978	26.1 °C	13 mm	232	0
1977	45.7 °C8 August 1977	0.2 °C14 January 1977	26.0 °C	59 mm	229	0
1976	44.7 °C6 August 1976	1.8 °C2 January 1976	25.3 °C	55 mm	215	0
1975	45.7 °C30 July 1975	-0.4 °C13 February 1975	25.1 °C	63 mm	203	1
1974	45.4 °C8 August 1974	0.8 °C26 January 1974	25.3 °C	82 mm	216	0
1973	45.8 °C14 August 1973	-1.3 °C5 January 1973	25.8 °C	20 mm	233	2
1972	45.8 °C28 July 1972	-0.5 °C26 December 1972	24.8 °C	87 mm	216	1
1971	44.5 °C13 July 1971	0.5 °C22 December 1971	24.9 °C	36 mm	218	0
1970	45.1 °C5 August 1970	-0.1 °C16 December 1970	25.6 °C	16 mm	219	1
1969	45.7 °C25 June 1969	0.0 °C5 February 1969	26.1 °C	60 mm	237	0
1968	45.7 °C28 July 1968	0.1 °C5 February 1968	25.5 °C	45 mm	225	0
1967	45.8 °C16 July 1967	-2.1 °C26 December 1967	24.8 °C	31 mm	213	2
1966	45.5 °C14 June 1966	3.1 °C3 January 1966	25.9 °C	17 mm	215	0
1965	44.8 °C25 June 1965	-1.5 °C22 December 1965	25.2 °C	33 mm	215	1
1964	46.6 °C1 August 1964	-4.0 °C20 January 1964	24.3 °C	161 mm	216	10
1963	45.2 °C19 July 1963	-3.3 °C28 December 1963	25.3 °C	61 mm	226	3
1962	45.5 °C20 July 1962	0.6 °C20 January 1962	25.8 °C	28 mm	241	0
1961	44.8 °C30 July 1961	2.2 °C31 December 1961	25.1 °C	33 mm	207	0
1960	45.4 °C21 August 1960	1.1 °C31 January 1960	25.8 °C	21 mm	225	0
1959	45.0 °C27 June 1959	0.5 °C16 December 1959	24.7 °C	68 mm	222	0
1958	45.5 °C22 July 1958	-0.4 °C1 January 1958	25.8 °C	49 mm	241	1
1957	46.0 °C15 August 1957	-1.8 °C26 January 1957	25.0 °C	61 mm	227	6
1956	45.5 °C7 August 1956	-0.9 °C18 January 1956	24.8 °C	17 mm	228	2
1955	45.0 °C21 July 1955	2.2 °C4 February 1955	25.3 °C	56 mm	232	0
1954	46.1 °C2 July 1954	2.9 °C23 January 1954	25.9 °C	16 mm	239	0
1953	46.4 °C24 July 1953	-1.7 °C23 December 1953	25.7 °C	65 mm	235	2
1952	45.7 °C8 June 1952	0.1 °C15 February 1952	25.7 °C	30 mm	233	0
1951	46.5 °C18 July 1951	0.6 °C27 January 1951	25.8 °C	19 mm	219	0
1950	44.3 °C31 May 1950	-4.1 °C29 January 1950	24.5 °C	31 mm	219	7
1949	44.9 °C10 July 1949	-3.1 °C3 January 1949	24.1 °C	51 mm	211	9
1948	45.1 °C14 July 1948	1.0 °C31 December 1948	24.8 °C	107 mm	195	0
1947	44.8 °C18 June 1947	1.5 °C28 December 1947	25.3 °C	65 mm	219	0
1946	43.8 °C24 July 1946	-0.9 °C15 January 1946	25.0 °C	15 mm	214	1
1945	44.5 °C5 July 1945	-2.2 °C29 January 1945	24.9 °C	14 mm	223	2
1944	44.7 °C2 July 1944	2.2 °C20 December 1944	25.1 °C	63 mm	233	0
1943	45.5 °C8 July 1943	0.6 °C5 February 1943	24.9 °C	66 mm	219	0
1942	45.6 °C25 June 1942	-0.9 °C8 January 1942	26.1 °C	67 mm	247	1
1941	44.9 °C26 July 1941	3.5 °C3 February 1941	25.6 °C	6 mm	224	0
1940	44.0 °C30 July 1940	-1.1 °C17 January 1940	24.7 °C	21 mm	207	2

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?

Year

Across the whole year

Average daily high

34.3 °C

+1.0 °C

Hot days (≥ 30 °C)

232 d/yr

Frost days (< 0 °C)

0 d/yr

-1

Annual rainfall

41 mm

-6 mm

Month by month

	High	vs. normal	Precipitation	vs. normal
Jan	20.2 °C	-0.6 °C	3 mm	-5 mm
Feb	22.4 °C	-1.3 °C	11 mm	+5 mm
Mar	28.1 °C	-0.3 °C	11 mm	+2 mm
Apr	37.6 °C	+3.8 °C	0 mm	-8 mm
May	41.8 °C	+2.4 °C	0 mm	-2 mm
Jun	43.6 °C	+1.3 °C	0 mm	0 mm
Jul	44.6 °C	+1.3 °C	0 mm	-0 mm
Aug	44.4 °C	+1.4 °C	0 mm	0 mm
Sep	41.7 °C	+1.6 °C	0 mm	0 mm
Oct	35.1 °C	+0.5 °C	0 mm	-1 mm
Nov	28.8 °C	+1.2 °C	0 mm	-5 mm
Dec	22.7 °C	+0.7 °C	16 mm	+7 mm

The year's extremes

Hottest day

46.9 °C

16 Jun 2025

Coldest day

3.6 °C

4 Jan 2025

Wettest day

7.4 mm

18 Dec 2025

Windiest day

36.7 km/h

6 Mar 2025

Strongest gust

55.4 km/h

6 Mar 2025

Hottest feels-like

46.2 °C

28 Jul 2025

Coldest feels-like

-0.5 °C

4 Jan 2025

Sunniest day

12.8 h

17 May 2025

What was the weather like that day?

Your birthday, a wedding, a memorable trip: discover the actual weather for any date since 1940.

Date

Frequently asked questions

What is the climate of Ad Dilam?

Ad Dilam has a hot desert climate (Köppen BWh). Over 1940-2025, the average annual temperature is 26.2 °C and it receives 47 mm of precipitation per year.

What is the hottest day ever recorded in Ad Dilam?

The hottest day measured in Ad Dilam between 1940 and 2025 was 17 July 2012, reaching 48.4 °C.

What is the coldest day in Ad Dilam?

The coldest day measured in Ad Dilam between 1940 and 2025 was 29 January 1950, at -4.1 °C.

Does it snow in Ad Dilam?

Almost never: Ad Dilam sees virtually no snow, with about 1 frost days per year.

Has the climate of Ad Dilam warmed?

Yes: Ad Dilam warmed by +3.5 °C between 1940 and 2025, a statistically significant trend.

What is the wettest day in Ad Dilam?

The wettest day measured in Ad Dilam between 1940 and 2025 was 26 April 2013, with 43 mm of rain in 24 hours.

What was the windiest day in Ad Dilam?

The windiest day measured in Ad Dilam between 1940 and 2025 was 4 May 1952, with winds reaching 48.6 km/h.

What is the warmest month in Ad Dilam?

The warmest month in Ad Dilam is July (36.1 °C on average); the coldest is January (14.3 °C).

How much does it rain in Ad Dilam?

Ad Dilam receives on average 47 mm of precipitation per year, spread over about 10 rainy days.

Is it sunny in Ad Dilam?

Ad Dilam gets on average 11.2 hours of sunshine per day, roughly 4,088 hours per year over 1940-2025.

Are there tropical nights in Ad Dilam?

Yes: Ad Dilam has on average 179 tropical nights per year (temperature staying above 20 °C), over 1940-2025.

What was the most extreme apparent temperature in Ad Dilam?

In Ad Dilam, between 1940 and 2025, the highest apparent temperature reached 48.4 °C on 12 August 2003, and the lowest was -10.5 °C on 20 January 1964.

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