Hilo weather in May
In May, Hilo sees average daytime highs of 74°F and overnight lows near 69°F, with 5.7 in of rain across 23.7 wet days and about 12.9 hours of daylight. It is the 7th-warmest and 8th-wettest month of the year here.
Day-to-day highs hold fairly steady near 74°F through the month. The sky is clear or mostly clear about 25% of the time in May, and the air most often feels muggy.
Daylight stretches from about 12 h 42 min at the start of May to 13 h 06 min by month's end. Set against the rest of the year, May is Hilo's 8th-clearest and 7th-windiest month. For the whole year in context, see Hilo's year-round climate.
- Daytime high
- 74°
- 7th warmest
- Overnight low
- 69°
- 6th coldest
- Rainfall
- 5.7 in
- 23.7 wet days
- Daylight
- 12 h 54 min
- 5:49 AM – 6:45 PM
- Cloud cover
- 58%
- 8th clearest
- Wind
- 6 mph
- 7th windiest
- Solar energy
- 6.49 kWh/m²
- Travel score
- 4.9
- out of 10
Hilo is human settlement and census-designated place in Hawaii, United States.
- Density
- 287/km²
- people per km²
Air quality: WHO Ambient Air Quality Database. Density & description: Wikidata (CC0), GeoNames.
Temperature in May
Day-to-day highs hold fairly steady near 74°F through the month.
A typical May day in Hilo reaches about 74°F in the afternoon and slips back to 69°F overnight — a 5°F spread between the day's warmth and the night's chill. On most days the high lands between 72°F and 77°F. Set against its neighbours, May runs on par with April and on par with June.
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | 31 | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg high (°F) | 74 | 74 | 74 | 74 | 74 | 74 | 74 | 74 | 74 | 74 | 74 | 74 | 74 | 74 | 74 | 74 | 74 | 74 | 74 | 75 | 75 | 75 | 75 | 75 | 75 | 75 | 75 | 75 | 75 | 75 | 75 |
| Avg low (°F) | 68 | 68 | 68 | 69 | 69 | 69 | 69 | 69 | 69 | 69 | 69 | 69 | 69 | 69 | 69 | 69 | 69 | 69 | 69 | 69 | 69 | 69 | 69 | 69 | 69 | 70 | 70 | 70 | 70 | 70 | 70 |
| Avg high (°F) | Avg low (°F) | |
|---|---|---|
| 1 | 74 | 68 |
| 2 | 74 | 68 |
| 3 | 74 | 68 |
| 4 | 74 | 69 |
| 5 | 74 | 69 |
| 6 | 74 | 69 |
| 7 | 74 | 69 |
| 8 | 74 | 69 |
| 9 | 74 | 69 |
| 10 | 74 | 69 |
| 11 | 74 | 69 |
| 12 | 74 | 69 |
| 13 | 74 | 69 |
| 14 | 74 | 69 |
| 15 | 74 | 69 |
| 16 | 74 | 69 |
| 17 | 74 | 69 |
| 18 | 74 | 69 |
| 19 | 74 | 69 |
| 20 | 75 | 69 |
| 21 | 75 | 69 |
| 22 | 75 | 69 |
| 23 | 75 | 69 |
| 24 | 75 | 69 |
| 25 | 75 | 69 |
| 26 | 75 | 70 |
| 27 | 75 | 70 |
| 28 | 75 | 70 |
| 29 | 75 | 70 |
| 30 | 75 | 70 |
| 31 | 75 | 70 |
Hilo weather by month
How May compares with the rest of the year at a glance. May is the 7th-warmest and 8th-wettest month here — the current month is highlighted below.
| Month | High / Low (°F) | Rainfall (inches) | Wet days | Daylight (hours) | Travel score |
|---|---|---|---|---|---|
| Jan | 73° / 67° | 5.8 | 16.8 | 10.9 | 6.0 |
| Feb | 72° / 67° | 6.6 | 17.2 | 11.3 | 5.5 |
| Mar | 72° / 67° | 9.1 | 23.5 | 11.9 | 4.7 |
| Apr | 73° / 68° | 7.1 | 24.8 | 12.4 | 4.5 |
| May | 74° / 69° | 5.7 | 23.7 | 12.9 | 4.9 |
| Jun | 75° / 70° | 4.7 | 24.1 | 13.2 | 4.8 |
| Jul | 76° / 71° | 5.7 | 25.8 | 13.1 | 4.6 |
| Aug | 77° / 72° | 6.7 | 25.6 | 12.7 | 4.6 |
| Sep | 77° / 72° | 4.5 | 22 | 12.1 | 5.1 |
| Oct | 77° / 71° | 5.4 | 23 | 11.5 | 5.0 |
| Nov | 75° / 70° | 7.5 | 23.2 | 11.1 | 4.8 |
| Dec | 73° / 68° | 7.9 | 22.2 | 10.8 | 5.1 |
Cloud cover in May
The sky is clear or mostly clear about 25% of the time in May.
Beyond those clear spells, partly cloudy skies cover about 33% of May, with mostly cloudy or overcast conditions the remaining 43%.
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | 31 | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Clearer (%) | 52 | 52 | 53 | 53 | 53 | 54 | 54 | 54 | 54 | 55 | 55 | 55 | 55 | 56 | 57 | 57 | 58 | 58 | 58 | 58 | 59 | 59 | 60 | 60 | 61 | 62 | 63 | 63 | 64 | 64 | 65 |
| Cloudier (%) | 48 | 48 | 47 | 47 | 47 | 46 | 46 | 46 | 46 | 45 | 45 | 45 | 45 | 44 | 43 | 43 | 42 | 42 | 42 | 42 | 41 | 41 | 40 | 40 | 39 | 38 | 37 | 37 | 36 | 36 | 35 |
| Clearer (%) | Cloudier (%) | |
|---|---|---|
| 1 | 52 | 48 |
| 2 | 52 | 48 |
| 3 | 53 | 47 |
| 4 | 53 | 47 |
| 5 | 53 | 47 |
| 6 | 54 | 46 |
| 7 | 54 | 46 |
| 8 | 54 | 46 |
| 9 | 54 | 46 |
| 10 | 55 | 45 |
| 11 | 55 | 45 |
| 12 | 55 | 45 |
| 13 | 55 | 45 |
| 14 | 56 | 44 |
| 15 | 57 | 43 |
| 16 | 57 | 43 |
| 17 | 58 | 42 |
| 18 | 58 | 42 |
| 19 | 58 | 42 |
| 20 | 58 | 42 |
| 21 | 59 | 41 |
| 22 | 59 | 41 |
| 23 | 60 | 40 |
| 24 | 60 | 40 |
| 25 | 61 | 39 |
| 26 | 62 | 38 |
| 27 | 63 | 37 |
| 28 | 63 | 37 |
| 29 | 64 | 36 |
| 30 | 64 | 36 |
| 31 | 65 | 35 |
Chance of precipitation in May
Hilo gets around 5.7 in of rain over 23.7 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 77% and peaks near 80% on the wettest days.
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | 31 | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Rain chance (%) | 80 | 79 | 79 | 79 | 78 | 78 | 77 | 77 | 77 | 77 | 77 | 77 | 77 | 76 | 76 | 76 | 76 | 76 | 76 | 76 | 76 | 76 | 76 | 76 | 76 | 76 | 76 | 76 | 76 | 76 | 77 |
| Rain chance (%) | |
|---|---|
| 1 | 80 |
| 2 | 79 |
| 3 | 79 |
| 4 | 79 |
| 5 | 78 |
| 6 | 78 |
| 7 | 77 |
| 8 | 77 |
| 9 | 77 |
| 10 | 77 |
| 11 | 77 |
| 12 | 77 |
| 13 | 77 |
| 14 | 76 |
| 15 | 76 |
| 16 | 76 |
| 17 | 76 |
| 18 | 76 |
| 19 | 76 |
| 20 | 76 |
| 21 | 76 |
| 22 | 76 |
| 23 | 76 |
| 24 | 76 |
| 25 | 76 |
| 26 | 76 |
| 27 | 76 |
| 28 | 76 |
| 29 | 76 |
| 30 | 76 |
| 31 | 77 |
Humidity in May
Most of May feels muggy — the stacked bands show each day's mix of comfort levels, read off the dew point.
By dew point, May lands in the muggy band about 55% of days. Sticky, muggy-or-worse air turns up on roughly 57% of them.
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | 31 | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Comfortable (%) | 3 | 3 | 3 | 3 | 3 | 3 | 3 | 3 | 3 | 2 | 2 | 2 | 2 | 1 | 1 | 1 | 1 | 1 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
| Humid (%) | 54 | 53 | 52 | 52 | 51 | 51 | 50 | 49 | 49 | 48 | 47 | 46 | 45 | 44 | 43 | 42 | 41 | 40 | 40 | 39 | 38 | 37 | 36 | 34 | 33 | 32 | 31 | 30 | 29 | 28 | 26 |
| Muggy (%) | 42 | 43 | 44 | 44 | 45 | 45 | 46 | 47 | 47 | 48 | 49 | 51 | 52 | 53 | 54 | 55 | 56 | 57 | 58 | 59 | 60 | 61 | 62 | 64 | 65 | 66 | 67 | 69 | 70 | 71 | 73 |
| Oppressive (%) | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 2 | 2 | 2 | 2 | 2 | 2 | 2 | 2 | 2 | 2 | 2 | 2 | 2 | 2 | 1 | 1 | 1 | 1 |
| Comfortable (%) | Humid (%) | Muggy (%) | Oppressive (%) | |
|---|---|---|---|---|
| 1 | 3 | 54 | 42 | 1 |
| 2 | 3 | 53 | 43 | 1 |
| 3 | 3 | 52 | 44 | 1 |
| 4 | 3 | 52 | 44 | 1 |
| 5 | 3 | 51 | 45 | 1 |
| 6 | 3 | 51 | 45 | 1 |
| 7 | 3 | 50 | 46 | 1 |
| 8 | 3 | 49 | 47 | 1 |
| 9 | 3 | 49 | 47 | 1 |
| 10 | 2 | 48 | 48 | 1 |
| 11 | 2 | 47 | 49 | 1 |
| 12 | 2 | 46 | 51 | 1 |
| 13 | 2 | 45 | 52 | 1 |
| 14 | 1 | 44 | 53 | 2 |
| 15 | 1 | 43 | 54 | 2 |
| 16 | 1 | 42 | 55 | 2 |
| 17 | 1 | 41 | 56 | 2 |
| 18 | 1 | 40 | 57 | 2 |
| 19 | 0 | 40 | 58 | 2 |
| 20 | 0 | 39 | 59 | 2 |
| 21 | 0 | 38 | 60 | 2 |
| 22 | 0 | 37 | 61 | 2 |
| 23 | 0 | 36 | 62 | 2 |
| 24 | 0 | 34 | 64 | 2 |
| 25 | 0 | 33 | 65 | 2 |
| 26 | 0 | 32 | 66 | 2 |
| 27 | 0 | 31 | 67 | 2 |
| 28 | 0 | 30 | 69 | 1 |
| 29 | 0 | 29 | 70 | 1 |
| 30 | 0 | 28 | 71 | 1 |
| 31 | 0 | 26 | 73 | 1 |
Wind in May
Winds average 6 mph in May.
Across May, daily wind ranges from about 6 mph on the calmest days to 7 mph at its breeziest. It stays fairly steady from day to day.
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | 31 | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Wind speed (mph) | 7 | 7 | 7 | 7 | 7 | 7 | 7 | 7 | 7 | 7 | 7 | 7 | 7 | 7 | 7 | 6 | 6 | 6 | 6 | 6 | 6 | 6 | 6 | 6 | 6 | 6 | 6 | 6 | 6 | 6 | 6 |
| Feels | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm |
| Wind speed (mph) | Feels | |
|---|---|---|
| 1 | 7 | calm |
| 2 | 7 | calm |
| 3 | 7 | calm |
| 4 | 7 | calm |
| 5 | 7 | calm |
| 6 | 7 | calm |
| 7 | 7 | calm |
| 8 | 7 | calm |
| 9 | 7 | calm |
| 10 | 7 | calm |
| 11 | 7 | calm |
| 12 | 7 | calm |
| 13 | 7 | calm |
| 14 | 7 | calm |
| 15 | 7 | calm |
| 16 | 6 | calm |
| 17 | 6 | calm |
| 18 | 6 | calm |
| 19 | 6 | calm |
| 20 | 6 | calm |
| 21 | 6 | calm |
| 22 | 6 | calm |
| 23 | 6 | calm |
| 24 | 6 | calm |
| 25 | 6 | calm |
| 26 | 6 | calm |
| 27 | 6 | calm |
| 28 | 6 | calm |
| 29 | 6 | calm |
| 30 | 6 | calm |
| 31 | 6 | calm |
Sunrise & sunset in May
Daylight runs from about 12 h 42 min at the start of May to 13 h 06 min by month's end. The lit band spans sunrise to sunset each day.
Days grow by about 24 minutes over May. Sunrise moves from 5:56 AM to 5:45 AM, and sunset from 6:39 PM to 6:51 PM.
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | 31 | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Daylight (h) | 12.7 | 12.7 | 12.7 | 12.8 | 12.8 | 12.8 | 12.8 | 12.8 | 12.8 | 12.8 | 12.9 | 12.9 | 12.9 | 12.9 | 12.9 | 12.9 | 12.9 | 13.0 | 13.0 | 13.0 | 13.0 | 13.0 | 13.0 | 13.0 | 13.0 | 13.0 | 13.1 | 13.1 | 13.1 | 13.1 | 13.1 |
| Sunrise (AM) | 5:56 | 5:56 | 5:55 | 5:54 | 5:54 | 5:53 | 5:53 | 5:52 | 5:52 | 5:51 | 5:51 | 5:50 | 5:50 | 5:49 | 5:49 | 5:49 | 5:48 | 5:48 | 5:48 | 5:47 | 5:47 | 5:47 | 5:46 | 5:46 | 5:46 | 5:46 | 5:46 | 5:45 | 5:45 | 5:45 | 5:45 |
| Sunset (PM) | 6:39 | 6:39 | 6:40 | 6:40 | 6:40 | 6:41 | 6:41 | 6:41 | 6:42 | 6:42 | 6:43 | 6:43 | 6:43 | 6:44 | 6:44 | 6:45 | 6:45 | 6:45 | 6:46 | 6:46 | 6:47 | 6:47 | 6:47 | 6:48 | 6:48 | 6:49 | 6:49 | 6:49 | 6:50 | 6:50 | 6:51 |
| Daylight (h) | Sunrise (AM) | Sunset (PM) | |
|---|---|---|---|
| 1 | 12.7 | 5:56 | 6:39 |
| 2 | 12.7 | 5:56 | 6:39 |
| 3 | 12.7 | 5:55 | 6:40 |
| 4 | 12.8 | 5:54 | 6:40 |
| 5 | 12.8 | 5:54 | 6:40 |
| 6 | 12.8 | 5:53 | 6:41 |
| 7 | 12.8 | 5:53 | 6:41 |
| 8 | 12.8 | 5:52 | 6:41 |
| 9 | 12.8 | 5:52 | 6:42 |
| 10 | 12.8 | 5:51 | 6:42 |
| 11 | 12.9 | 5:51 | 6:43 |
| 12 | 12.9 | 5:50 | 6:43 |
| 13 | 12.9 | 5:50 | 6:43 |
| 14 | 12.9 | 5:49 | 6:44 |
| 15 | 12.9 | 5:49 | 6:44 |
| 16 | 12.9 | 5:49 | 6:45 |
| 17 | 12.9 | 5:48 | 6:45 |
| 18 | 13.0 | 5:48 | 6:45 |
| 19 | 13.0 | 5:48 | 6:46 |
| 20 | 13.0 | 5:47 | 6:46 |
| 21 | 13.0 | 5:47 | 6:47 |
| 22 | 13.0 | 5:47 | 6:47 |
| 23 | 13.0 | 5:46 | 6:47 |
| 24 | 13.0 | 5:46 | 6:48 |
| 25 | 13.0 | 5:46 | 6:48 |
| 26 | 13.0 | 5:46 | 6:49 |
| 27 | 13.1 | 5:46 | 6:49 |
| 28 | 13.1 | 5:45 | 6:49 |
| 29 | 13.1 | 5:45 | 6:50 |
| 30 | 13.1 | 5:45 | 6:50 |
| 31 | 13.1 | 5:45 | 6:51 |
Solar energy in May
Average shortwave solar energy reaching the ground each day in May, about 6.49 kWh/m².
For context, solar energy here swings from a low near 4.17 kWh/m² to a high of 6.68 kWh/m² in June across the year — May's 6.49 kWh/m² sits near the top of that range.
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | 31 | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Solar energy (kWh/m²) | 6.3 | 6.3 | 6.3 | 6.4 | 6.4 | 6.4 | 6.4 | 6.4 | 6.4 | 6.4 | 6.4 | 6.4 | 6.4 | 6.4 | 6.5 | 6.5 | 6.5 | 6.5 | 6.5 | 6.5 | 6.5 | 6.5 | 6.6 | 6.6 | 6.6 | 6.6 | 6.6 | 6.6 | 6.6 | 6.6 | 6.6 |
| Level | Intense | Intense | Intense | Intense | Intense | Intense | Intense | Intense | Intense | Intense | Intense | Intense | Intense | Intense | Intense | Intense | Intense | Intense | Intense | Intense | Intense | Intense | Intense | Intense | Intense | Intense | Intense | Intense | Intense | Intense | Intense |
| Solar energy (kWh/m²) | Level | |
|---|---|---|
| 1 | 6.3 | Intense |
| 2 | 6.3 | Intense |
| 3 | 6.3 | Intense |
| 4 | 6.4 | Intense |
| 5 | 6.4 | Intense |
| 6 | 6.4 | Intense |
| 7 | 6.4 | Intense |
| 8 | 6.4 | Intense |
| 9 | 6.4 | Intense |
| 10 | 6.4 | Intense |
| 11 | 6.4 | Intense |
| 12 | 6.4 | Intense |
| 13 | 6.4 | Intense |
| 14 | 6.4 | Intense |
| 15 | 6.5 | Intense |
| 16 | 6.5 | Intense |
| 17 | 6.5 | Intense |
| 18 | 6.5 | Intense |
| 19 | 6.5 | Intense |
| 20 | 6.5 | Intense |
| 21 | 6.5 | Intense |
| 22 | 6.5 | Intense |
| 23 | 6.6 | Intense |
| 24 | 6.6 | Intense |
| 25 | 6.6 | Intense |
| 26 | 6.6 | Intense |
| 27 | 6.6 | Intense |
| 28 | 6.6 | Intense |
| 29 | 6.6 | Intense |
| 30 | 6.6 | Intense |
| 31 | 6.6 | Intense |
Hazard calendar for Hilo
In May, Hilo sits inside its pacific hurricane season. The full year is below, with each hazard's peak months called out.
Hilo sits in the eastern Pacific hurricane zone; the season peaks August–September.
Is May a good time to visit Hilo?
Our two travel scores rate May for general sightseeing and for beach or pool weather — 0 (poor) to 10 (ideal).
May is a reasonable time to visit Hilo for sightseeing.
What to pack for Hilo in May
From May's temperature range, rain chance, sun and wind — what's worth putting in the bag.
In May, Hilo sees daytime highs around 74°F and nights near 69°F. Pack rain gear and sun protection. Worth having: light clothes. About 24 days see rain.
Sea temperature near Hilo in May
The nearest coast averages about 77°F in May — the other half of the beach question. The full-year curve and swim-comfort zones are below.
The sea at the nearest coast (about 11 mi away) is warmest in September at about 80°F and coldest in March near 75°F.
The water stays above 68°F all year — warm enough for a swim any month.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Sea temperature (°F) | 76 | 75 | 75 | 76 | 77 | 78 | 79 | 79 | 80 | 80 | 78 | 77 |
| Comfort | Warm | Warm | Warm | Warm | Warm | Warm | Warm | Warm | Warm | Warm | Warm | Warm |
| Sea temperature (°F) | Comfort | |
|---|---|---|
| Jan | 76 | Warm |
| Feb | 75 | Warm |
| Mar | 75 | Warm |
| Apr | 76 | Warm |
| May | 77 | Warm |
| Jun | 78 | Warm |
| Jul | 79 | Warm |
| Aug | 79 | Warm |
| Sep | 80 | Warm |
| Oct | 80 | Warm |
| Nov | 78 | Warm |
| Dec | 77 | Warm |
UV index in Hilo in May
Clear-sky midday UV in May peaks around 11 (very high — sun protection essential). The full-year curve, shaded by WHO exposure level, is below.
Under clear skies, the midday UV index in Hilo peaks around August 15 at about 14 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near December 16 at about 7 (high).
The index reaches 3 or more — the level where the WHO recommends sun protection — every month of the year.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| UV index (midday) | 8 | 10 | 12 | 14 | 11 | 13 | 13 | 14 | 13 | 10 | 8 | 7 |
| Level | Very high | Very high | Extreme | Extreme | Extreme | Extreme | Extreme | Extreme | Extreme | Extreme | Very high | High |
| UV index (midday) | Level | |
|---|---|---|
| Jan | 8 | Very high |
| Feb | 10 | Very high |
| Mar | 12 | Extreme |
| Apr | 14 | Extreme |
| May | 11 | Extreme |
| Jun | 13 | Extreme |
| Jul | 13 | Extreme |
| Aug | 14 | Extreme |
| Sep | 13 | Extreme |
| Oct | 10 | Extreme |
| Nov | 8 | Very high |
| Dec | 7 | High |
Air quality in Hilo in May
Average fine-particle pollution (PM2.5) through the year — so you can see where May falls, not just the annual average.
Air quality in Hilo is worst in January — around 28 µg/m³ PM2.5 (moderate), about 1.7× the cleanest month (July, 16 µg/m³).
Modeled monthly averages (CAMS reanalysis, 2015–2024).
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| PM2.5 (µg/m³) | 28 | 27 | 26 | 23 | 22 | 19 | 16 | 18 | 21 | 25 | 22 | 24 |
| Level | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate |
| PM2.5 (µg/m³) | Level | |
|---|---|---|
| Jan | 28 | Moderate |
| Feb | 27 | Moderate |
| Mar | 26 | Moderate |
| Apr | 23 | Moderate |
| May | 22 | Moderate |
| Jun | 19 | Moderate |
| Jul | 16 | Moderate |
| Aug | 18 | Moderate |
| Sep | 21 | Moderate |
| Oct | 25 | Moderate |
| Nov | 22 | Moderate |
| Dec | 24 | Moderate |
Where is Hilo?
Hilo sits at 19.7°N, 155.1°W, 59 ft above sea level, in United States. The nearest listed city is Kīhei, 113 mi away.
Topography around Hilo
How much the land rises and falls, and what covers it, within 2, 10 and 50 miles of Hilo.
Within 2 miles, the terrain around Hilo has only modest variations in elevation — a maximum elevation change of 774 ft around an average of 197 ft above sea level; within 10 miles, large variations in elevation — a maximum elevation change of 3,606 ft; within 50 miles, extreme variations in elevation — a maximum elevation change of 13,750 ft.
The land around Hilo is covered by trees (34%), water (29%) and grassland (22%) within 2 miles, trees (42%) and water (29%) within 10 miles, and water (49%) and grassland (20%) within 50 miles.
United States travel facts
- Power plugs
- Type A / B
- 120 V · 60 Hz
- Prices
- ≈ 100% of US
- price level, 2025
- GDP per capita
- $90,027
- 2025
- Happiness
- 6.8 / 10
- World Happiness, 2025
- Safe drinking water
- 98%
- of population, 2024
- Homicide rate
- 5.8
- per 100k, 2023
- Road deaths
- 12.7
- per 100k/yr, 2019
- Income group
- High
- World Bank
- Religion
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 Hilo (19.7299°, -155.0907°, elevation 59 ft), 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).