Chongming climate

Name: Chongming
Address: CN

Chongming is warmest in July, with average highs of 30 °C, and coldest in January, when nights average 2.5 °C. June is the wettest month (258 mm) and December the driest (43 mm). Figures are 1991–2020 climate normals.

Across a full year Chongming averages 1,280 mm of rain, 103 days above 25 °C and 13 days below freezing.

China · population 637,921 · 1991–2020 normals

Temperature below 0 °C to above 30 °C Rain band height is that month’s share of the wettest month

Warmest month July 30 °C
Coldest month January 2.5 °C
Driest month December 43 mm
Wettest month June 258 mm
Least cloud October 51 % cloud
Hottest on record July 40 °C
Coldest on record January -8.8 °C
Warmest sea August 27 °C

What to expectChongming through the year

Chongming has a clear annual cycle: average daily highs run from 7.4 °C in January to 30 °C in July, a swing of 23 °C in mean temperature across the year.

Counted across a normal year, 103 days a year reach 25 °C, 32 of them reach 30 °C, 13 nights drop below freezing. The warmest reading in the 1991–2020 record is 40 °C, in July.

Rain is strongly seasonal. June averages 258 mm against 43 mm in December — 6.0 times as much. Planning around the dry months matters more here than planning around temperature.

The sea off Chongming is warmest in August at 27 °C and coldest in February at 6.9 °C. Sea temperature lags the air by a month or two, which is why late summer swims warmer than early summer at the same air temperature.

Month by month

Month	Avg high	Rainfall	Cloud
January	7.4 °C	62 mm	60 %
February	8.6 °C	60 mm	62 %
March	12.2 °C	91 mm	66 %
April	17.4 °C	99 mm	66 %
May	22.4 °C	120 mm	67 %
June	25.6 °C	258 mm	78 %
July	29.6 °C	170 mm	69 %
August	29.5 °C	160 mm	60 %
September	26.0 °C	99 mm	56 %
October	21.5 °C	60 mm	51 %
November	16.3 °C	59 mm	53 %
December	10.1 °C	43 mm	51 %

Temperature month by month

Month	Avg high	Avg low	Mean	Record high	Record low	Days above 25 °C	Days above 30 °C	Days below 0 °C
January	7.4 °C	2.5 °C	5.0 °C	20.4 °C	-8.8 °C	0	0	6
February	8.6 °C	3.6 °C	6.0 °C	21.3 °C	-4.2 °C	0	0	3
March	12.2 °C	7.0 °C	9.4 °C	24.4 °C	-2.3 °C	0	0	0
April	17.4 °C	12.0 °C	14.4 °C	28.7 °C	1.4 °C	1	0	0
May	22.4 °C	17.4 °C	19.5 °C	32.5 °C	8.1 °C	5	0	0
June	25.6 °C	21.6 °C	23.3 °C	36.0 °C	15.0 °C	16	2	0
July	29.6 °C	25.8 °C	27.4 °C	40.3 °C	18.6 °C	29	15	0
August	29.5 °C	26.0 °C	27.5 °C	37.5 °C	20.3 °C	30	13	0
September	26.0 °C	22.4 °C	24.0 °C	34.5 °C	14.8 °C	19	1	0
October	21.5 °C	17.2 °C	19.2 °C	29.0 °C	9.0 °C	2	0	0
November	16.3 °C	11.5 °C	13.8 °C	25.1 °C	-1.3 °C	0	0	0
December	10.1 °C	5.0 °C	7.6 °C	20.7 °C	-6.8 °C	0	0	3

Rain, sun and wind month by month

Month	Rainfall	Wet days	Daylight	Cloud cover	Humidity	Wind	Sea temp
January	62 mm	8	10 h/day	60 %	74 %	19 km/h	8.0 °C
February	60 mm	8	11 h/day	62 %	76 %	19 km/h	6.9 °C
March	91 mm	10	12 h/day	66 %	77 %	21 km/h	9.2 °C
April	99 mm	10	13 h/day	66 %	78 %	21 km/h	13.3 °C
May	120 mm	9	14 h/day	67 %	80 %	20 km/h	18.2 °C
June	258 mm	14	14 h/day	78 %	85 %	18 km/h	21.7 °C
July	170 mm	14	14 h/day	69 %	85 %	19 km/h	25.6 °C
August	160 mm	15	13 h/day	60 %	84 %	20 km/h	27.1 °C
September	99 mm	10	12 h/day	56 %	79 %	19 km/h	25.4 °C
October	60 mm	5	11 h/day	51 %	74 %	18 km/h	21.6 °C
November	59 mm	7	11 h/day	53 %	74 %	18 km/h	17.3 °C
December	43 mm	6	10 h/day	51 %	72 %	19 km/h	12.3 °C

How Chongming compares

The same four figures for nearby destinations, so the numbers above have something to be read against. Summer high is the warmest month's average high; winter low is the coldest month's average low.

Destination	Summer high	Winter low	Rain per year	Days above 25 °C
Chongming	30 °C	2.5 °C	1,280 mm	103
Baoshan · China	31 °C	1.5 °C	1,286 mm	119
Shanghai · China	31 °C	1.4 °C	1,317 mm	124
Qibao · China	31 °C	1.1 °C	1,342 mm	129
Kunshan · China	32 °C	0.4 °C	1,299 mm	136
Qingpu · China	32 °C	0.6 °C	1,341 mm	136
Songjiang · China	32 °C	0.8 °C	1,371 mm	136

Where Chongming ranks

Ranking	Position	Value
Best beach destinations in Asia in September	44thof 50	85/100

Planning a trip? See the best time to visit Chongming.

QuestionsCommon questions about Chongming’s climate

When is the best time to visit Chongming?

That depends on what you want, so the honest answer is a comparison rather than a single month. May, June, October sit closest to 20 °C on average, July is the warmest month and December the driest. The month-by-month table above has the full picture.

How hot does Chongming get?

In July, the warmest month, daily highs average 30 °C. About 32 days a year pass 30 °C. The highest value in the 1991–2020 record is 40 °C.

How cold does it get in winter?

Nights average 2.5 °C in January, the coldest month. A normal year has 13 nights below freezing.

Which month is wettest in Chongming?

June, averaging 258 mm over 14 days with rain. The driest month is December with 43 mm. The year as a whole averages 1,280 mm.

Are these figures a forecast?

No. They are 1991–2020 climate normals: the average of thirty years, which describes what a month is usually like in Chongming rather than what any particular week will bring. Individual years can differ substantially from the normal.

Data sources and method

ERA5 / ERA5-Land reanalysis — Copernicus Climate Change Service (C3S), ECMWF. Copernicus Licence
Open-Meteo — Open-Meteo.com. CC BY 4.0
NOAA OISST v2.1 — NOAA Physical Sciences Laboratory. Public domain
GeoNames — GeoNames.org. CC BY 4.0

Normal period: 1991–2020
Dataset version: era5-1991-2020-scores1.1
Last processed: 1 August 2026

Measured values come from ERA5 reanalysis and are reproduced unchanged. Calculated by us: monthly rankings, daylight hours, beach and comfort scores. Full formulas are on the methodology page.

Contains modified Copernicus Climate Change Service information 2026. Neither the European Commission nor ECMWF is responsible for any use that may be made of the Copernicus information or data it contains.