Lasem weather in May

In May, Lasem sees average daytime highs of 30°C and overnight lows near 26°C, with 100 mm of rain across 16.8 wet days and about 11.7 hours of daylight. It is the 5th-warmest and 7th-wettest month of the year here.

Day-to-day highs hold fairly steady near 30°C through the month. The sky is clear or mostly clear about 30% of the time in May, and the air most often feels miserable.

Daylight stretches from about 11 h 48 min at the start of May to 11 h 36 min by month's end. Set against the rest of the year, May is Lasem's 5th-clearest and 9th-windiest month. For the whole year in context, see Lasem's year-round climate.

Daytime high
30°
5th warmest
Overnight low
26°
12th coldest
Rainfall
100 mm
16.8 wet days
Daylight
11 h 42 min
5:40 AM – 5:21 PM
Cloud cover
60%
5th clearest
Wind
9 km/h
9th windiest
Solar energy
5.32 kWh/m²
Travel score
4.3
out of 10

Temperature in May

Average highAverage lowShaded bands: 10–90% of days

Day-to-day highs hold fairly steady near 30°C through the month.

A typical May day in Lasem reaches about 30°C in the afternoon and slips back to 26°C overnight — a 4°C spread between the day's warmth and the night's chill. On most days the high lands between 29°C and 31°C. Set against its neighbours, May runs on par with April and on par with June.

20°25°30°35°151015202531
Avg high (°C)Avg low (°C)
13026
23026
33026
43026
53026
63026
73026
83026
93026
103026
113026
123026
133026
143026
153026
163026
173026
183026
193026
203026
213026
223026
233026
243026
253026
263026
273026
283026
293026
303026
313026

How May really feels in Lasem

Once humidity and wind are folded in, May averages 31 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
31
heat index over the day's high
Days feeling ≤ C
0
wind chill below the day's low

The story in May is heat — humidity pushes the afternoon "feels like" well above the raw temperature.

Lasem weather by month

How May compares with the rest of the year at a glance. May is the 5th-warmest and 7th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysDaylight (hours)Travel score
Jan29° / 25°28428.912.32.9
Feb29° / 25°24926.412.22.9
Mar29° / 25°23128.1123.0
Apr30° / 26°19224.511.93.3
May30° / 26°10016.811.74.3
Jun30° / 25°6410.711.65.0
Jul30° / 25°355.811.75.7
Aug30° / 24°133.411.85.9
Sep31° / 25°254.5125.4
Oct31° / 25°8713.212.14.3
Nov30° / 25°18923.412.33.2
Dec30° / 25°28128.312.42.9

Cloud cover in May

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 30% 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 51%. Skies tend to open up as the month goes on.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
13763
23862
33862
44060
54060
64060
74060
84159
94159
104357
114555
124654
134852
144951
155050
165149
175347
185446
195545
205644
215644
225644
235644
245743
255743
265644
275644
285644
295545
305446
315446

Chance of precipitation in May

Any precipitation

Lasem gets around 100 mm of rain over 16.8 wet days in May. The line is the day-by-day chance of measurable precipitation.

Day to day, the chance of measurable rain averages around 54% and peaks near 69% on the wettest days. The odds ease toward the end of the month.

0%20%40%60%80%151015202531
Rain chance (%)
169
268
367
466
566
665
764
863
962
1060
1159
1258
1356
1455
1554
1653
1751
1850
1949
2048
2147
2247
2346
2445
2545
2644
2744
2844
2943
3043
3143

Humidity in May

DryComfortableHumidMuggyOppressiveMiserable

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

By dew point, May lands in the miserable band about 58% of days. Sticky, muggy-or-worse air turns up on roughly 100% of them.

0%25%50%75%100%151015202531
Muggy (%)Oppressive (%)Miserable (%)
102476
202575
302674
412772
512871
612970
713168
813267
913366
1013465
1123563
1223662
1323761
1423860
1523959
1624058
1724157
1824256
1924355
2024454
2124553
2224652
2324751
2424849
2524948
2625147
2725246
2825246
2925345
3025444
3125543

Wind in May

Winds average 9 km/h in May.

Across May, daily wind ranges from about 9 km/h on the calmest days to 10 km/h at its breeziest. It stays fairly steady from day to day.

051015151015202531
Wind speed (km/h)Feels
19calm
29calm
39calm
49calm
59calm
69calm
79calm
89calm
99calm
109calm
119calm
129calm
139calm
149calm
159calm
169calm
179calm
189calm
199calm
209calm
219calm
229calm
2310calm
2410calm
2510calm
2610calm
2710calm
2810calm
2910calm
3010calm
3110calm

Sunrise & sunset in May

DaylightNight

Daylight runs from about 11 h 48 min at the start of May to 11 h 36 min by month's end. The lit band spans sunrise to sunset each day.

Days shrink by about 12 minutes over May. Sunrise moves from 5:38 AM to 5:42 AM, and sunset from 5:24 PM to 5:21 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
111.85:385:24
211.85:385:24
311.85:385:24
411.85:385:24
511.75:385:23
611.75:395:23
711.75:395:23
811.75:395:23
911.75:395:22
1011.75:395:22
1111.75:395:22
1211.75:395:22
1311.75:395:22
1411.75:395:22
1511.75:395:21
1611.75:405:21
1711.75:405:21
1811.75:405:21
1911.75:405:21
2011.75:405:21
2111.75:405:21
2211.75:405:21
2311.75:415:21
2411.75:415:21
2511.75:415:21
2611.75:415:21
2711.75:415:21
2811.75:425:21
2911.65:425:21
3011.65:425:21
3111.65:425:21

Solar energy in May

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in May, about 5.32 kWh/m².

For context, solar energy here swings from a low near 4.98 kWh/m² to a high of 6.76 kWh/m² in September across the year — May's 5.32 kWh/m² falls in the middle.

0246151015202531
Solar energy (kWh/m²)Level
15.3Bright
25.3Bright
35.3Bright
45.3Bright
55.3Bright
65.3Bright
75.3Bright
85.3Bright
95.3Bright
105.3Bright
115.3Bright
125.3Bright
135.3Bright
145.3Bright
155.3Bright
165.3Bright
175.3Bright
185.3Bright
195.3Bright
205.3Bright
215.3Bright
225.3Bright
235.3Bright
245.3Bright
255.3Bright
265.3Bright
275.3Bright
285.2Bright
295.2Bright
305.2Bright
315.2Bright
Planning a trip in May

Hazard calendar for Lasem

In seasonPeak

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

Lasem sits in the South Indian Ocean cyclone belt; the season peaks January–March.

Lasem's rainy season runs November–April, when most of the year's rain falls.

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

Is May a good time to visit Lasem?

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

4.3
Sightseeing
5th-best month of the year
5.8
Beach & pool
6th-best month of the year

May is a reasonable time to visit Lasem for sightseeing.

What to pack for Lasem in May

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

In May, Lasem sees daytime highs around 30°C and nights near 26°C. Pack light clothes and rain gear. Worth having: sun protection. About 17 days see rain.

light clothesrain gearsun protection

Sea temperature near Lasem in May

The nearest coast averages about 30°C in May — the other half of the beach question. The full-year curve and swim-comfort zones are below.

The sea offshore is warmest in November at about 30°C and coldest in August near 28°C.

The water stays above 20°C all year — warm enough for a swim any month.

26°28°30°32°JanFebMarAprMayJunJulAugSepOctNovDecwarmtropicalcomfortable to swim
Sea temperature (°C)Comfort
Jan29Tropical
Feb29Tropical
Mar29Tropical
Apr30Tropical
May30Tropical
Jun29Tropical
Jul29Tropical
Aug28Tropical
Sep29Tropical
Oct29Tropical
Nov30Tropical
Dec30Tropical

UV index in Lasem in May

LowModerateHighVery highExtreme

Clear-sky midday UV in May peaks around 9 (very high — sun protection essential). The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Lasem peaks around March 17 at about 14 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near June 16 at about 8 (very high).

The index reaches 3 or more — the level where the WHO recommends sun protection — every month of the year.

025710JanFebMarAprMayJunJulAugSepOctNovDecExtremeVery highExtremeVery highMar 17UV 14Jun 16UV 8
UV index (midday)Level
Jan10Extreme
Feb10Extreme
Mar14Extreme
Apr11Extreme
May9Very high
Jun8Very high
Jul9Very high
Aug11Extreme
Sep12Extreme
Oct12Extreme
Nov7Very high
Dec11Extreme

Air quality in Lasem 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 Lasem is worst in May — around 40 µg/m³ PM2.5 (poor), and holds fairly steady the rest of the year.

Modeled monthly averages (CAMS reanalysis, 2015–2024).

0204060JanFebMarAprMayJunJulAugSepOctNovDecModeratePoorModeratePoorModerateMay 1839 µg/m³Feb 1126 µg/m³
PM2.5 (µg/m³)Level
Jan27Moderate
Feb25Moderate
Mar32Moderate
Apr35Poor
May40Poor
Jun37Poor
Jul34Moderate
Aug33Moderate
Sep35Poor
Oct39Poor
Nov34Moderate
Dec30Moderate
Location & terrain

Where is Lasem?

Lasem sits at 6.7°S, 111.5°E, 12 m above sea level, in Indonesia. The nearest listed city is Rembangan, 12 km away.

Topography around Lasem

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

Within 3 km, the terrain around Lasem has significant variations in elevation — a maximum elevation change of 251 m around an average of 28 m above sea level; within 16 km, large variations in elevation — a maximum elevation change of 787 m; within 80 km, very significant variations in elevation — a maximum elevation change of 1,559 m.

The land around Lasem is covered by trees (38%) and cropland (21%) within 3 km, water (40%) and trees (34%) within 16 km, and water (36%), trees (35%) and cropland (24%) within 80 km.

3 km
251 m
16 km
787 m
80 km
1,559 m
treesgrasslandcroplandartificial surfacesbare terrainwater
May weather nearby: Rembangan 12 km · Blora 31 km · Juwana 33 km · Pati 46 km · Tayu 47 km · Cepu 53 km · Jekulo 59 km · Baekrajan 67 km

Indonesia travel facts

Travel advisory
Level 2
Exercise Increased Caution
Power plugs
Type C / F
230 V · 50 Hz
Prices
≈ 29% of US
price level, 2025
GDP per capita
$5,060
2025
Happiness
5.6 / 10
World Happiness, 2025
Safe drinking water
30%
of population, 2024
Homicide rate
0.3
per 100k, 2022
Road deaths
11.3
per 100k/yr, 2019
Income group
Upper middle
World Bank
English
Low
EF EPI 471
Religion
Muslim 87%Protestant 8%Roman Catholic 3%Hindu 2%

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 Lasem (-6.6922°, 111.4527°, elevation 12 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. Tropical-cyclone seasons are the published climatological basin seasons (NOAA National Hurricane Center / regional warning centres). Sea temperatures are the NOAA OISST v2.1 1991–2020 monthly climatology (public domain), sampled at the nearest ocean point. 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).