Climate averages 1991–2020

Negombo weather
in May.

A hot, very wet month: the 5th warmest and the 10th driest of the year.

Long-term climate patterns, not a forecast for a particular trip.

Average high 29.6°C Daytime mean, May
Average low 25.7°C Night-time mean, May
Rainfall 255 mm 29 days with ≥1 mm
Daylight 12 h Sunrise to sunset, per day
Every month in Negombo · average highYear overview

May is a hot month in Negombo: daytime highs average 29.6°C and nights cool to about 25.7°C. By daytime temperature it is the 5th warmest of the 12 months.

Expect about 255 mm of rain on roughly 29 days, which makes May a very wet month (the 10th driest of the 12 months). Daylight, from sunrise to sunset, lasts about 12 h 27 min on an average May day.

The nearest other city in this atlas is Colombo (30 km away). In May its highs average 29.5°C, about as warm as Negombo, with 279 mm of rain.

Among the 12 cities listed in Sri Lanka, Negombo ranks 7th of 12 for the warmest May highs and 9th of 12 for the driest May (rainfall, lowest first). The mean May high of those 12 cities is 30.6°C; Negombo is 1.0°C cooler than that mean.

From May to June, average highs fall by 0.8°C to 28.8°C, and monthly rainfall falls from 255 mm to 224 mm.

The annual picture

May in context

30-year average
Average highAverage low°C
Average daily high and low temperatures by month The same values are available in the monthly table below. Lines show mean daily maxima and minima, not a forecast interval. 20253035 JanFebMarAprMayJunJulAugSepOctNovDec

Monthly rainfall

Average total · mm
Average monthly rainfall totalsEach bar is a mean monthly total over 1991–2020. Full numbers are in the table. JanFebMarAprMayJunJulAugSepOctNovDec 3500

Averages from hourly ERA5 reanalysis data. Actual weather varies from year to year. How these numbers are calculated

Every month, side by side

Negombo climate table

1991–2020
Monthly climate averages for Negombo, 1991–2020
MonthAverage highHigh / lowAverage lowRainfall mm/monthRain days ≥1 mm/dayDaylight hours/dayDay­light h/day
January 30.2°C23.2°C23.2°C386.211.812 h
February 31.8°C23.7°C23.7°C406.511.912 h
March 31.8°C24.8°C24.8°C7615.812.112 h
April 30.7°C25.5°C25.5°C16326.012.312 h
May, selected 29.6°C25.7°C25.7°C25528.612.412 h
June 28.8°C25.4°C25.4°C22427.012.513 h
July 28.5°C25.2°C25.2°C17624.512.512 h
August 28.4°C25.0°C25.0°C16523.912.412 h
September 28.6°C24.9°C24.9°C21525.312.212 h
October 28.8°C24.5°C24.5°C31526.412.012 h
November 29.0°C24.0°C24.0°C27122.311.812 h
December 29.1°C23.5°C23.5°C13714.111.712 h

Rainfall is the average of the 30 separate monthly totals. A rain day is a local calendar day with at least 1 mm of precipitation. Daylight is the calculated sunrise-to-sunset length, not measured sunshine.

Compare places

May in nearby cities

Distance from Negombo

Read the numbers correctly

Climate, not a promise.

These patterns help compare months. They cannot tell you the weather on a specific day of your trip.

Sources, method and limits

How these numbers are made (what the highs, lows and rain days mean, the sources and the model cell used for Negombo) is explained once on the Negombo year overview and on the Sources, method and limits page.