Ratnapura, Sri Lanka climate

Af Tropical rainforest

Ratnapura has a remarkably steady tropical climate (Tropical rainforest, Köppen Af). The hottest month is April with an average daily high near 90°F, while the coldest is January averaging around 75°F at night. Precipitation totals about 94 inches a year and is strongly seasonal — November alone averages 13.4 inches while January barely receives 2.55 inches.

☀️ All year

Hot

Daytime highs near 90°F most of the year.

About 42 days a year above 90 °F

🌙 Nights

Stays warm

Even the coolest nights stay near 75°F.

🌧️ Rain

Very wet

About 94 in of rain a year.

Wettest in November

⛅ Sky & trend

Often cloudy

Cloudy skies much of the year.

Temperature & precipitation

Daily high–low temperature range with the monthly average, plus monthly precipitation · 1991–2020 normals · hover a month for the exact figures

Clear vs cloudy days

Share of days each month that are clear, partly cloudy or cloudy · 1991–2020 · hover a month for the day counts

Ratnapura climate normals (1991–2020)

	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
Avg high (°F)	88	89	89	90	89	86	87	86	86	86	87	87
Avg temp (°F)	82	83	84	86	85	83	83	83	83	83	83	82
Avg low (°F)	75	77	79	81	82	81	80	80	80	79	79	77
Precipitation (in)	2.6	3.4	4.1	10.6	12.3	7.0	3.8	4.5	10.9	11.4	13.4	10.1

Jan – Jun	Jan	Feb	Mar	Apr	May	Jun
Avg high (°F)	88	89	89	90	89	86
Avg temp (°F)	82	83	84	86	85	83
Avg low (°F)	75	77	79	81	82	81
Precipitation (in)	2.6	3.4	4.1	10.6	12.3	7.0

Jul – Dec	Jul	Aug	Sep	Oct	Nov	Dec
Avg high (°F)	87	86	86	86	87	87
Avg temp (°F)	83	83	83	83	83	82
Avg low (°F)	80	80	80	79	79	77
Precipitation (in)	3.8	4.5	10.9	11.4	13.4	10.1

How often — frequency of weather events

	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
Days with measurable rain (days)	3	4	6	9	12	11	7	8	11	12	11	8
Days with high ≥ 90°F (days)	5	6	7	11	7	0.5	0.1	0.3	—	0.2	2	3

Jan – Jun	Jan	Feb	Mar	Apr	May	Jun
Days with measurable rain (days)	3	4	6	9	12	11
Days with high ≥ 90°F (days)	5	6	7	11	7	0.5

Jul – Dec	Jul	Aug	Sep	Oct	Nov	Dec
Days with measurable rain (days)	7	8	11	12	11	8
Days with high ≥ 90°F (days)	0.1	0.3	—	0.2	2	3

Sky & atmosphere

	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
Cloud cover (%)	59	53	53	65	73	77	77	74	73	76	78	70
Clear days (≤ 30% cloud)	7	7	7	4	3	2	2	2	2	2	2	4
Partly cloudy days (30–70%)	10	12	15	11	9	8	9	10	9	9	8	10
Cloudy days (≥ 70%)	13	9	9	15	19	21	21	20	19	20	20	18
Relative humidity (%)	79	75	73	80	85	86	86	86	85	85	84	82
Wind speed (mph)	7.9	6.0	4.6	5.4	8.9	10.1	9.7	9.7	9.2	7.3	6.2	7.6

Jan – Jun	Jan	Feb	Mar	Apr	May	Jun
Cloud cover (%)	59	53	53	65	73	77
Clear days (≤ 30% cloud)	7	7	7	4	3	2
Partly cloudy days (30–70%)	10	12	15	11	9	8
Cloudy days (≥ 70%)	13	9	9	15	19	21
Relative humidity (%)	79	75	73	80	85	86
Wind speed (mph)	7.9	6.0	4.6	5.4	8.9	10.1

Jul – Dec	Jul	Aug	Sep	Oct	Nov	Dec
Cloud cover (%)	77	74	73	76	78	70
Clear days (≤ 30% cloud)	2	2	2	2	2	4
Partly cloudy days (30–70%)	9	10	9	9	8	10
Cloudy days (≥ 70%)	21	20	19	20	20	18
Relative humidity (%)	86	86	85	85	84	82
Wind speed (mph)	9.7	9.7	9.2	7.3	6.2	7.6

Methodology & sources

Temperature — modelled for this location from ERA5-Land reanalysis, a ~9 km global grid, because no long-record weather station is close enough to use.

Precipitation — 1991–2020 normals computed from 12 years of daily observations at Colombo, a weather station, about 64 km from the city centre. The underlying daily records come from NOAA's global station network.

Cloud, humidity, wind & sunshine — modelled estimates from NASA POWER, NASA's satellite-and-reanalysis climatology. This is the standard global source for atmospheric variables, which are not measured at most weather stations.

How we build these numbers →