United Kingdom · 1991–2020

Best time to visit
Castlereagh.

July leads for comfortable weather in Castlereagh: typically 19.2°C by day, 11.8°C at night, with 77 mm of rain. Based on measured 1991–2020 NOAA station history.

Best comfortJuly

Typical high19.2°C

Typical low11.8°C

Rain in July77 mm

Comfort

July

July · August · June

64climate match

Beach

July

July · August · June

28climate match

Outdoors

June

June · July · September

76climate match

The weakest month is January, scoring 6 against July’s 64 — days reach only 8.1°C, 16° below the 24°C the score treats as ideal.

Month by month

The whole year,
without the guesswork.

The bars show the comfort score. Day and night temperatures come from daily observed highs and lows; rain is the historical monthly estimate.

Jan

68.1° / 2.5°

Feb

128.6° / 2.5°

Mar

1910.3° / 3.4°

Apr

3212.6° / 5°

May

4515.4° / 7.2°

Jun

5717.6° / 10°

Jul

6419.2° / 11.8°

Aug

6018.9° / 11.6°

Sep

5416.9° / 10°

Oct

3413.6° / 7.4°

Nov

1610.6° / 4.7°

Dec

88.4° / 2.9°

Monthly climate evidence for Castlereagh — daylight is calculated from latitude, everything else is measured, sea temperature from the nearest open water 33 km away
Month	Day	Night	Rain	Wet days	Sea	Daylight	Comfort	Coverage
January	8.1°C	2.5°C	89 mm	15.1	9.0°C	7 h 49	6	Strong coverage
February	8.6°C	2.5°C	73 mm	13.3	8.1°C	9 h 36	12	Strong coverage
March	10.3°C	3.4°C	73 mm	13.4	7.7°C	11 h 39	19	Strong coverage
April	12.6°C	5°C	64 mm	11.6	8.3°C	13 h 59	32	Strong coverage
May	15.4°C	7.2°C	68 mm	12.3	9.6°C	16 h 02	45	Strong coverage
June	17.6°C	10°C	74 mm	11.5	11.6°C	17 h 14	57	Strong coverage
July	19.2°C	11.8°C	77 mm	12.4	13.2°C	16 h 45	64	Strong coverage
August	18.9°C	11.6°C	86 mm	13.6	14.0°C	14 h 55	60	Strong coverage
September	16.9°C	10°C	75 mm	11.5	14.0°C	12 h 38	54	Strong coverage
October	13.6°C	7.4°C	98 mm	13.5	13.5°C	10 h 23	34	Strong coverage
November	10.6°C	4.7°C	106 mm	15.8	12.2°C	8 h 21	16	Strong coverage
December	8.4°C	2.9°C	95 mm	14.5	10.6°C	7 h 17	8	Strong coverage

What has changed

Castlereagh runs +1.1°C
on the 1961–1990 baseline.

Each bar compares the 2011–2025 daytime average for that month against the same month in 1961–1990, measured at the same station. Months where the older record is too thin to compare are left blank.

Jan

+0.9

Feb

+1.8

Mar

+1.4

Apr

+1.3

May

+1.5

Jun

+0.9

Jul

+0.9

Aug

+0.7

Sep

+0.9

Oct

+0.7

Nov

+1.2

Dec

+1.0

July daytime highs, 2011–2025. Last recorded: 20.4°C.

Records at STORMONT CASTLE, 1960–2026
Month	Record high	Record low	Wettest day	Wettest / driest month	Years
January	14.7°C25 Jan 2003	-9.9°C12 Jan 1982	37 mm19 Jan 1973	187 mm2026 · driest 21 mm in 2006	67
February	15.8°C13 Feb 1998	-6.1°C16 Feb 1969	38 mm6 Feb 1963	178 mm1966 · driest 4 mm in 1986	65
March	20.1°C27 Mar 2012	-7.2°C2 Mar 1965	51 mm30 Mar 2010	147 mm2024 · driest 17 mm in 1961	67
April	21.6°C29 Apr 2025	-5.6°C29 Apr 1973	41 mm15 Apr 1986	139 mm1991 · driest 6 mm in 1980	67
May	25.0°C22 May 2010	-1.7°C2 May 1979	52 mm13 May 1993	197 mm1993 · driest 6 mm in 1991	67
June	29.0°C27 Jun 2018	1.7°C1 Jun 1962	52 mm27 Jun 2012	222 mm2012 · driest 22 mm in 1992	66
July	29.7°C11 Jul 1983	5.6°C10 Jul 1971	49 mm4 Jul 1971	130 mm2023 · driest 11 mm in 1982	66
August	28.2°C20 Aug 1995	4.9°C24 Aug 1986	92 mm15 Aug 1970	192 mm2008 · driest 6 mm in 1995	66
September	25.8°C7 Sep 2023	1.1°C28 Sep 1974	80 mm24 Sep 2012	175 mm1999 · driest 2 mm in 2014	66
October	20.6°C8 Oct 1969	-0.9°C30 Oct 1988	56 mm14 Oct 1976	212 mm2023 · driest 25 mm in 1978	65
November	17.1°C1 Nov 2007	-3.4°C28 Nov 2010	47 mm1 Nov 1968	247 mm2002 · driest 33 mm in 1989	66
December	15.0°C6 Dec 2016	-9.1°C22 Dec 2010	46 mm28 Dec 1978	273 mm1978 · driest 14 mm in 1971	66

Typical days per month at STORMONT CASTLE, 1991–2020
Month	Days 25°C+	Frost nights	Heavy rain (10 mm+)
January	0	5	2
February	0	5	2
March	0	3	2
April	0	<1	2
May	0	0	2
June	<1	0	2
July	<1	0	2
August	<1	0	3
September	0	0	2
October	0	<1	3
November	0	1	4
December	0	4	3

How often, not how much — every day in STORMONT CASTLE’s record sorted by what it was actually like, rather than averaged
Month	Warm & dry days	Wet days	Washouts	Week with 3+ wet days	Daytime mean has ranged
January	0%	49%	9%	67%	5.9–9.2°C
February	0%	44%	7%	58%	5.9–9.8°C
March	<1%	44%	6%	60%	7.8–11.6°C
April	<1%	37%	5%	51%	10.3–13.6°C
May	6%	39%	4%	53%	13.5–16.7°C
June	17%	37%	6%	49%	15.8–19.0°C
July	24%	37%	6%	52%	17.3–20.7°C
August	20%	42%	8%	57%	17.2–20.4°C
September	5%	41%	8%	58%	15.3–17.8°C
October	<1%	44%	10%	63%	12.2–14.8°C
November	0%	48%	10%	68%	8.6–11.6°C
December	0%	46%	8%	64%	6.5–9.9°C

A warm and dry day reaches 20°C with under 1 mm of rain; a wet day gets 1 mm or more; a washout gets 10 mm or more. The week column is the share of seven-day stretches in that month, across the station’s whole daily record, that contained three or more wet days — the odds a week-long trip is rained on repeatedly, counted rather than modelled. The last column is the 10th to 90th percentile of that month’s daytime average across individual years: a narrow band means the average is what you will get, a wide one means the average is a midpoint between years that felt quite different.

1960Each stripe is one year’s mean temperature against the 61-year average. Warmest: 2025. Coolest: 1979.2025

The evidence behind this page

Nearby, measured,
and named.

Place identity: GeoNames 2653558
NOAA station: UKE00105877 · STORMONT CASTLE
Station distance: 4.9 km from the place centre
Climate period: 1991–2020
Minimum month coverage: 28 usable years
Daylight: Calculated from latitude 54.57°, mid-month, sunrise to sunset including refraction. Not a station measurement.
Sea temperature: NOAA OISST v2.1 1991–2020 monthly climatology, nearest open water 33 km from the place centre. A sheltered bay can run warmer than the open sea it is measured from.
Important limit: Historical climate is not a forecast. Nearby stations can miss mountains, coasts, and local microclimates.

These places read the same station, so their numbers are identical — distance from STORMONT CASTLE is what differs

Belfast→Newtownabbey→Bangor→Newtownards→Carrickfergus→Larne→

Or put two places side by side: Castlereagh vs Belfast

Best time to visitCastlereagh.

July

July

June

The whole year,without the guesswork.

Castlereagh runs +1.1°Con the 1961–1990 baseline.

Nearby, measured,and named.

Best time to visit
Castlereagh.

The whole year,
without the guesswork.

Castlereagh runs +1.1°C
on the 1961–1990 baseline.

Nearby, measured,
and named.