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Hilo, Hawaii climate

Af Tropical rainforest

Hilo has a remarkably steady warm-temperate climate (Tropical rainforest, Köppen Af). The hottest month is August with an average daily high near 28°C, while the coldest is February averaging around 18°C at night. Around 3058 mm of precipitation falls each year, peaking in November (366 mm) and easing off in May (178 mm).

☀️ All year

Warm

Daytime highs near 28°C most of the year.

About 2 days a year above 32 °C

🌙 Nights

Stays warm

Even the coolest nights stay near 18°C.

🌧️ Rain

Very wet

About 3058 mm of rain a year.

Wettest in November

⛅ Sky & trend

Partly cloudy

A roughly even mix of sun and cloud.

−0.1 °C vs 50 years ago

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

Hilo climate normals (1991–2020)

	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
Avg high (°C)	26	26	26	26	27	28	28	28	29	28	27	26
Avg temp (°C)	22	22	22	23	23	24	25	25	25	24	23	22
Avg low (°C)	18	18	18	19	20	20	21	21	21	21	20	19
Precipitation (mm)	200	260	322	239	178	185	235	287	221	260	366	307

Jan – Jun	Jan	Feb	Mar	Apr	May	Jun
Avg high (°C)	26	26	26	26	27	28
Avg temp (°C)	22	22	22	23	23	24
Avg low (°C)	18	18	18	19	20	20
Precipitation (mm)	200	260	322	239	178	185

Jul – Dec	Jul	Aug	Sep	Oct	Nov	Dec
Avg high (°C)	28	28	29	28	27	26
Avg temp (°C)	25	25	25	24	23	22
Avg low (°C)	21	21	21	21	20	19
Precipitation (mm)	235	287	221	260	366	307

How often — frequency of weather events

	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
Days with measurable rain (days)	16	16	22	25	23	25	27	27	23	23	23	22
Days with high ≥ 32°C (days)	0.1	0.0	0.1	—	0.0	—	0.2	0.1	0.7	0.3	0.1	—

Jan – Jun	Jan	Feb	Mar	Apr	May	Jun
Days with measurable rain (days)	16	16	22	25	23	25
Days with high ≥ 32°C (days)	0.1	0.0	0.1	—	0.0	—

Jul – Dec	Jul	Aug	Sep	Oct	Nov	Dec
Days with measurable rain (days)	27	27	23	23	23	22
Days with high ≥ 32°C (days)	0.2	0.1	0.7	0.3	0.1	—

Sky & atmosphere

	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
Cloud cover (%)	52	54	61	61	57	53	53	52	55	58	58	53
Clear days (≤ 30% cloud)	4	3	1	0.2	0.9	1	1	0.9	0.8	1	2	4
Partly cloudy days (30–70%)	21	18	19	21	23	25	25	26	24	22	19	20
Cloudy days (≥ 70%)	7	7	10	9	7	4	5	4	6	8	9	8
Relative humidity (%)	81	80	81	81	81	81	82	81	82	82	83	82
Wind speed (mph)	8.3	8.9	9.3	9.8	9.1	9.6	9.6	9.6	9.0	8.9	9.4	9.2

Jan – Jun	Jan	Feb	Mar	Apr	May	Jun
Cloud cover (%)	52	54	61	61	57	53
Clear days (≤ 30% cloud)	4	3	1	0.2	0.9	1
Partly cloudy days (30–70%)	21	18	19	21	23	25
Cloudy days (≥ 70%)	7	7	10	9	7	4
Relative humidity (%)	81	80	81	81	81	81
Wind speed (mph)	8.3	8.9	9.3	9.8	9.1	9.6

Jul – Dec	Jul	Aug	Sep	Oct	Nov	Dec
Cloud cover (%)	53	52	55	58	58	53
Clear days (≤ 30% cloud)	1	0.9	0.8	1	2	4
Partly cloudy days (30–70%)	25	26	24	22	19	20
Cloudy days (≥ 70%)	5	4	6	8	9	8
Relative humidity (%)	82	81	82	82	83	82
Wind speed (mph)	9.6	9.6	9.0	8.9	9.4	9.2

Methodology & sources

Temperature & precipitation — the official 1991–2020 climate normals from NOAA's U.S. Climate Normals, measured at Hilo Intl AP 87 (NOAA GHCN station USW00021504), about 5 km from the city centre.

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 →