Hainan weather in May

In May, Hainan sees average daytime highs of 20°C and overnight lows near 8°C, with 62 mm of precipitation across 9.9 wet days and about 14.8 hours of daylight. It is the 4th-warmest and 5th-wettest month of the year here.

Highs climb over the month, from about 17°C in the first days to 22°C by the end. The sky is clear or mostly clear about 22% of the time in May, and the air most often feels dry.

Daylight stretches from about 14 h 12 min at the start of May to 15 h 24 min by month's end. Set against the rest of the year, May is Hainan's 10th-clearest and 2nd-windiest month. For the whole year in context, see Hainan's year-round climate.

Daytime high
20°
4th warmest
Overnight low
8th coldest
Precipitation
62 mm
9.9 wet days
Daylight
14 h 54 min
4:02 AM – 6:54 PM
Cloud cover
64%
10th clearest
Wind
13 km/h
2nd windiest
Solar energy
5.78 kWh/m²
Travel score
6.2
out of 10
Air quality
Elevated
PM2.5 25 µg/m³ · 2018

Air quality: WHO Ambient Air Quality Database. Density & description: Wikidata (CC0), GeoNames.

Temperature in May

Average highAverage lowShaded bands: 10–90% of days

Highs climb over the month, from about 17°C in the first days to 22°C by the end.

A typical May day in Hainan reaches about 20°C in the afternoon and slips back to 8°C overnight — a 12°C spread between the day's warmth and the night's chill. On most days the high lands between 14°C and 26°C. Set against its neighbours, May runs about 8°C warmer than April and about 5°C cooler than June.

10°20°30°151015202531
Avg high (°C)Avg low (°C)
1174
2175
3175
4175
5175
6186
7186
8186
9186
10197
11197
12197
13197
14208
15208
16208
17208
18219
19219
20219
21219
222110
232210
242210
252210
262210
272211
282211
292211
302311
312312

How May really feels in Hainan

Once humidity and wind are folded in, May averages 0 days that feel above 32°C and 0 that feel at or below 0°C — the comfort signal a plain temperature reading hides.

Days feeling ≥ 32°C
0
heat index over the day's high
Days feeling ≤ C
0
wind chill below the day's low

May sits comfortably in between — no days that feel dangerously hot or drop to a hard freeze once humidity and wind are folded in.

Hainan weather by month

How May compares with the rest of the year at a glance. May is the 4th-warmest and 5th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysSnow daysDaylight (hours)Travel score
Jan-15° / -26°41.11.68.70.0
Feb-9° / -22°61.61.9100.0
Mar / -11°163.63.311.60.1
Apr12° / 335.61.213.33.2
May20° / 629.90.114.86.2
Jun25° / 15°10113.3015.66.1
Jul27° / 18°16214.7015.35.8
Aug25° / 16°14313.60146.2
Sep20° / 739.1012.46.4
Oct10° / -0°376.90.910.62.7
Nov-3° / -12°143.22.99.10.0
Dec-13° / -23°82.63.48.30.0

Cloud cover in May

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 22% of the time in May.

Beyond those clear spells, partly cloudy skies cover about 20% of May, with mostly cloudy or overcast conditions the remaining 58%.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
14357
24357
34357
44357
54357
64159
74159
84159
94159
104159
114159
124159
134159
144159
154258
164258
174357
184357
194258
204258
214258
224258
234258
244258
254258
264258
274258
284357
294357
304357
314258

Chance of precipitation in May

Any precipitation

Hainan gets around 62 mm of rain and snow over 9.9 wet days in May. The line is the day-by-day chance of measurable precipitation.

Day to day, the chance of measurable precipitation averages around 32% and peaks near 37% on the wettest days, and about 0 day brings snow. The odds climb toward the end of the month.

0%10%20%30%40%50%151015202531
Rain chance (%)
125
225
326
426
527
628
729
830
930
1031
1131
1232
1332
1432
1532
1632
1733
1833
1933
2033
2133
2233
2334
2434
2534
2634
2734
2835
2935
3036
3137

Humidity in May

DryComfortableHumidMuggyOppressiveMiserable

Most of May feels dry — the stacked bands show each day's mix of comfort levels, read off the dew point.

By dew point, May lands in the dry band about 98% of days. It rarely turns muggy — the humid and sticky bands barely register.

0%25%50%75%100%151015202531
Dry (%)Comfortable (%)Humid (%)
110000
210000
310000
410000
510000
610000
710000
810000
910000
1010000
1110000
1210000
1310000
149910
159910
169910
179910
189910
199910
209910
219910
229820
239820
249730
259631
269541
279451
289361
299181
308992
3187112

Wind in May

Winds average 13 km/h in May.

Across May, daily wind ranges from about 12 km/h on the calmest days to 14 km/h at its breeziest. It stays fairly steady from day to day.

05101520151015202531
Wind speed (km/h)Feels
114light breeze
214light breeze
314light breeze
414light breeze
514light breeze
614light breeze
714light breeze
814light breeze
913light breeze
1013light breeze
1113light breeze
1213light breeze
1313light breeze
1413light breeze
1513light breeze
1613light breeze
1713light breeze
1813light breeze
1913light breeze
2013light breeze
2113light breeze
2213light breeze
2313light breeze
2413light breeze
2513light breeze
2613light breeze
2712light breeze
2812light breeze
2912light breeze
3012light breeze
3112light breeze

Sunrise & sunset in May

DaylightNight

Daylight runs from about 14 h 12 min at the start of May to 15 h 24 min by month's end. The lit band spans sunrise to sunset each day.

Days grow by about 72 minutes over May. Sunrise moves from 4:24 AM to 3:48 AM, and sunset from 6:34 PM to 7:11 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
114.24:246:34
214.24:236:36
314.34:216:37
414.34:196:38
514.44:186:40
614.44:166:41
714.54:156:42
814.54:136:44
914.64:126:45
1014.64:106:46
1114.64:096:48
1214.74:086:49
1314.74:066:50
1414.84:056:52
1514.84:046:53
1614.94:026:54
1714.94:016:56
1814.94:006:57
1915.03:596:58
2015.03:586:59
2115.13:577:00
2215.13:557:02
2315.13:547:03
2415.23:537:04
2515.23:527:05
2615.23:527:06
2715.33:517:07
2815.33:507:08
2915.33:497:09
3015.43:487:10
3115.43:487:11

Solar energy in May

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in May, about 5.78 kWh/m² — the sunniest month for solar.

For context, solar energy here swings from a low near 1.53 kWh/m² to a high of 5.78 kWh/m² in May across the year — May's 5.78 kWh/m² sits near the top of that range.

0246151015202531
Solar energy (kWh/m²)Level
15.5Bright
25.5Bright
35.5Bright
45.5Bright
55.6Bright
65.6Bright
75.6Bright
85.6Bright
95.6Bright
105.7Bright
115.7Bright
125.7Bright
135.7Bright
145.8Bright
155.8Bright
165.8Bright
175.8Bright
185.8Bright
195.9Bright
205.9Bright
215.9Bright
225.9Bright
235.9Bright
245.9Bright
255.9Bright
265.9Bright
275.9Bright
285.9Bright
295.9Bright
305.9Bright
315.9Bright
Planning a trip in May

Hazard calendar for Hainan

In seasonPeak

None of Hainan's seasonal hazards are active in May. The full-year calendar below shows when the rainy season, cyclone risk and dust haze do peak.

Hainan's rainy season runs June–September, when most of the year's rain falls.

Rainy season
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec

Is May a good time to visit Hainan?

Our two travel scores rate May for general sightseeing and for beach or pool weather — 0 (poor) to 10 (ideal).

6.2
Sightseeing
2nd-best month of the year
3.1
Beach & pool
4th-best month of the year

May is a reasonable time to visit Hainan for sightseeing.

What to pack for Hainan in May

From May's temperature range, rain chance, sun and wind — what's worth putting in the bag.

In May, Hainan sees daytime highs around 20°C and nights near 8°C. Worth packing: rain gear and sun protection. About 10 days see rain.

rain gearsun protection

UV index in Hainan in May

LowModerateHighVery highExtreme

Clear-sky midday UV in May peaks around 5 — enough to warrant sun protection. The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Hainan peaks around August 17 at about 7 (high) — sunscreen and a hat are worth it in the middle of the day. It bottoms out near December 19 at about 1 (low).

The index reaches 3 or more — the level where the WHO recommends sun protection — in 6 months of the year.

025710JanFebMarAprMayJunJulAugSepOctNovDecLowModerateHighHighModerateLowAug 17UV 7Dec 19UV 1
UV index (midday)Level
Jan1Low
Feb1Low
Mar3Moderate
Apr4Moderate
May5High
Jun6High
Jul5Moderate
Aug7Very high
Sep5Moderate
Oct2Moderate
Nov1Low
Dec1Low

Air quality in Hainan in May

GoodModeratePoorUnhealthyVery unhealthy

Average fine-particle pollution (PM2.5) through the year — so you can see where May falls, not just the annual average.

Air quality in Hainan is worst in March — around 37 µg/m³ PM2.5 (poor), about 2.3× the cleanest month (August, 16 µg/m³).

Seasonal pattern from CAMS reanalysis, scaled to Hainan's WHO annual average of 25 µg/m³.

010203040JanFebMarAprMayJunJulAugSepOctNovDecModerateModerateMar 1636 µg/m³Aug 2016 µg/m³
PM2.5 (µg/m³)Level
Jan31Moderate
Feb31Moderate
Mar37Poor
Apr30Moderate
May21Moderate
Jun19Moderate
Jul20Moderate
Aug16Moderate
Sep17Moderate
Oct22Moderate
Nov28Moderate
Dec27Moderate
Location & terrain

Where is Hainan?

Hainan sits at 47.2°N, 127.0°E, 0 m above sea level, in China. The nearest listed city is Harbin, 167 km away.

RaychikhinskBlagoveshchenskChigiriBelogorskSvobodnyyBirobidzhanNamyang-nodongjagu

Topography around Hainan

How much the land rises and falls, and what covers it, within 3, 16 and 80 km of Hainan.

Within 3 km, the terrain around Hainan has only modest variations in elevation — a maximum elevation change of 73 m around an average of 214 m above sea level; within 16 km, only modest variations in elevation — a maximum elevation change of 91 m; within 80 km, significant variations in elevation — a maximum elevation change of 538 m.

The land around Hainan is covered by cropland (87%) within 3 km, cropland (89%) within 16 km, and cropland (82%) within 80 km.

3 km
73 m
16 km
91 m
80 km
538 m
treesgrasslandcroplandartificial surfaceswater
May weather nearby: Harbin 167 km · Raychikhinsk 336 km · Blagoveshchensk 341 km · Chigiri 347 km · Belogorsk 424 km · Svobodnyy 468 km · Birobidzhan 475 km · Namyang-nodongjagu 526 km

China travel facts

Travel advisory
Level 2
Exercise Increased Caution
Power plugs
Type A / I
220 V · 50 Hz
Prices
≈ 47% of US
price level, 2025
GDP per capita
$13,862
2025
Happiness
6.1 / 10
World Happiness, 2025
Homicide rate
0.5
per 100k, 2020
Road deaths
17.4
per 100k/yr, 2019
Income group
Upper middle
World Bank
English
Low
EF EPI 464
Religion
unaffiliated 52%folk religion 22%Buddhist 18%Christian 5%

Sources: World Bank, US State Department, World Happiness Report, WHO/UNICEF, EF EPI, CIA World Factbook.

Data sources

Temperature, precipitation, cloud, humidity, wind and solar figures are a 1991–2020 climatology for Hainan (47.2322°, 126.9809°, elevation 0 m), computed from hourly ERA5 reanalysis — contains modified Copernicus Climate Change Service information. Sun figures are astronomical calculations, not observations. City data © GeoNames, CC BY 4.0. Map outlines from Natural Earth (public domain); interactive map © Google. UV index is derived from CAMS (Copernicus Atmosphere Monitoring Service) clear-sky UV data — contains modified Copernicus Atmosphere Monitoring Service information. Monthly air-quality (PM2.5) seasonality is from the CAMS EAC4 reanalysis (Copernicus Atmosphere Monitoring Service), scaled to the WHO annual mean where available. Topography is sampled from the Copernicus DEM GLO-90 elevation model (© ESA/Airbus) and ESA WorldCover 2021 land cover (CC BY 4.0).