Switzerland · 1991–2020

Best time to visit
Sierre.

June leads for comfortable weather in Sierre: typically 25.5°C by day, 12.9°C at night, with 48 mm of rain. Based on measured 1991–2020 NOAA station history.

Best comfortJune

Typical high25.5°C

Typical low12.9°C

Rain in June48 mm

Comfort

June

June · August · September

85climate match

Beach

July

July · August · June

67climate match

Outdoors

September

September · May · April

89climate match

The weakest month is January, scoring 5 against June’s 85 — days reach only 5.2°C, 19° 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

55.2° / -3.1°

Feb

137.9° / -2°

Mar

3913.7° / 1.7°

Apr

6017.9° / 5.2°

May

7621.9° / 9.2°

Jun

8525.5° / 12.9°

Jul

8027.4° / 14.4°

Aug

8226.5° / 14°

Sep

8221.9° / 10.4°

Oct

5616.9° / 6°

Nov

2310.1° / 1°

Dec

55.2° / -2.5°

Monthly climate evidence for Sierre — daylight is calculated from latitude, everything else is measured
Month	Day	Night	Rain	Wet days	Daylight	Comfort	Coverage
January	5.2°C	-3.1°C	52 mm	7.1	8 h 59	5	Strong coverage
February	7.9°C	-2°C	40 mm	5.6	10 h 15	13	Strong coverage
March	13.7°C	1.7°C	37 mm	5.9	11 h 45	39	Strong coverage
April	17.9°C	5.2°C	34 mm	5.2	13 h 29	60	Strong coverage
May	21.9°C	9.2°C	52 mm	7.5	14 h 57	76	Strong coverage
June	25.5°C	12.9°C	48 mm	7.4	15 h 46	85	Strong coverage
July	27.4°C	14.4°C	62 mm	8	15 h 27	80	Strong coverage
August	26.5°C	14°C	60 mm	8.2	14 h 10	82	Strong coverage
September	21.9°C	10.4°C	38 mm	5.9	12 h 29	82	Strong coverage
October	16.9°C	6°C	43 mm	6.5	10 h 49	56	Strong coverage
November	10.1°C	1°C	50 mm	6.9	9 h 21	23	Strong coverage
December	5.2°C	-2.5°C	68 mm	7.5	8 h 37	5	Strong coverage

What has changed

Sierre runs +2.1°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

+1.8

Feb

+2.2

Mar

+2.7

Apr

+2.5

May

+1.3

Jun

+3.1

Jul

+2.3

Aug

+3.0

Sep

+1.3

Oct

+1.3

Nov

+1.6

Dec

+1.5

June daytime highs, 2011–2025. Last recorded: 28.5°C.

Records at SION 2, 1955–2026
Month	Record high	Record low	Wettest day	Wettest / driest month	Years
January	16.8°C19 Jan 2007	-20.6°C16 Jan 1979	51 mm21 Jan 2018	197 mm2018 · driest 3 mm in 1989	71
February	21.4°C23 Feb 2017	-17.2°C1 Feb 1963	79 mm14 Feb 1990	264 mm1990 · driest 0 mm in 2012	71
March	26.6°C29 Mar 1968	-12.8°C6 Mar 1971	51 mm20 Mar 1978	152 mm2001 · driest 4 mm in 2025	71
April	30.2°C21 Apr 1968	-7.2°C8 Apr 1956	73 mm16 Apr 2025	106 mm1977 · driest 1 mm in 2007	71
May	35.1°C25 May 2009	-2.2°C8 May 1957	49 mm1 May 2015	121 mm2010 · driest 9 mm in 2008	71
June	37.0°C30 Jun 2019	1.5°C1 Jun 2006	39 mm20 Jun 1973	130 mm1974 · driest 9 mm in 1989	70
July	38.0°C24 Jul 2019	2.9°C22 Jul 1980	42 mm6 Jul 1986	154 mm2007 · driest 6 mm in 1983	71
August	37.6°C24 Aug 2023	3.9°C31 Aug 1995	58 mm6 Aug 2018	127 mm1956 · driest 13 mm in 1998	71
September	34.0°C17 Sep 1975	0.0°C16 Sep 1957	51 mm21 Sep 1968	134 mm2025 · driest 5 mm in 2019	71
October	27.4°C12 Oct 1967	-5.0°C30 Oct 1955	46 mm17 Oct 1980	122 mm2025 · driest 0 mm in 1985	71
November	21.1°C7 Nov 1955	-13.4°C30 Nov 1978	81 mm21 Nov 1971	186 mm2023 · driest 0 mm in 2011	71
December	17.5°C3 Dec 2003	-17.8°C27 Dec 1962	48 mm4 Dec 1992	181 mm1965 · driest 0 mm in 2016	71

Typical days per month at SION 2, 1991–2020
Month	Days 25°C+	Days 30°C+	Frost nights	Heavy rain (10 mm+)
January	0	0	24	2
February	0	0	20	1
March	0	0	9	<1
April	2	0	1	1
May	8	<1	0	2
June	17	5	0	2
July	23	8	0	2
August	20	7	0	2
September	7	<1	0	1
October	<1	0	2	1
November	0	0	12	2
December	0	0	23	2

The best month has moved. On the 1961–1990 numbers the strongest month here was June (scoring 89); on 2011–2025 it is September (88). Both are scored the same way, from the same station — only the climate underneath changed.

How often, not how much — every day in SION 2’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%	23%	6%	26%	2.3–7.4°C
February	<1%	21%	5%	25%	3.9–11.4°C
March	7%	20%	4%	23%	10.1–15.8°C
April	28%	20%	3%	20%	14.3–19.8°C
May	53%	23%	4%	23%	18.8–23.4°C
June	66%	26%	5%	30%	22.4–27.8°C
July	71%	26%	5%	28%	24.3–29.2°C
August	70%	28%	6%	31%	23.2–28.3°C
September	60%	22%	4%	23%	19.7–24.0°C
October	20%	22%	5%	25%	14.6–19.1°C
November	<1%	24%	6%	27%	7.7–12.1°C
December	0%	25%	7%	31%	2.8–6.8°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.

1955Each stripe is one year’s mean temperature against the 68-year average. Warmest: 2018. Coolest: 1956.2025

The evidence behind this page

Nearby, measured,
and named.

Place identity: GeoNames 2658606
NOAA station: SZE00105086 · SION 2
Station distance: 17.7 km from the place centre
Climate period: 1991–2020
Minimum month coverage: 29 usable years
Daylight: Calculated from latitude 46.29°, mid-month, sunrise to sunset including refraction. Not a station measurement.
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 SION 2 is what differs

Aosta→Sitten→Montreux→Ivrea→Martigny-Ville→Monthey→

Or put two places side by side: Sierre vs Aosta

Best time to visitSierre.

June

July

September

The whole year,without the guesswork.

Sierre runs +2.1°Con the 1961–1990 baseline.

Nearby, measured,and named.

Best time to visit
Sierre.

The whole year,
without the guesswork.

Sierre runs +2.1°C
on the 1961–1990 baseline.

Nearby, measured,
and named.