Hilo weather in May: Hilo, Hawaii: normal highs, lows, rain and records for May
Hilo in May has a normal high of 81°F and a normal low of 67°F, a daily mean of 74°F, rising from 80°F on the 1st to 81°F by the 31st. Measurable precipitation falls on 23 days in a normal May, 6.99 inches in all. (NOAA 1991-2020 normals)
In metric: a normal high of 27°C and low of 20°C, 178 mm of precipitation in May.
- NOAA stationHilo International Airport 87
- Station IDUSW00021504
- Location19.72°N 155.05°W
- Elevation38 ft (12 m)
- Population (census place)48,223
- Jan 79° 64°
- Feb 78° 64°
- Mar 79° 65°
- Apr 79° 66°
- May 81° 67°
- Jun 82° 69°
- Jul 83° 70°
- Aug 83° 70°
- Sep 83° 70°
- Oct 82° 69°
- Nov 80° 68°
- Dec 79° 66°
Each month: normal high (large) and low, °F. Fill: the month's normal mean, colder blue to hotter red.
How warm is Hilo in May?
The normal high is 81°F and the normal low 67°F, for a daily mean of 74.0°F. May is 1.5°F warmer than April and 1.2°F cooler than June. May is the 6th warmest month of the year in Hilo and the 12th wettest. Across the month the normal high rises 1°F, from 80°F on May 1 to 81°F on May 31. From one year to the next May's mean temperature typically moves about 1.0°F either way (NOAA's standard deviation), so roughly two Mays in three average between 73°F and 75°F.
Bars above: each day's normal high to low. Columns below: the chance of 0.01 inch or more of precipitation that day, on a scale of 0 to 100% (highest 79%).
| Day | High | Low | Chance of 0.01 in | Chance of 0.10 in |
|---|---|---|---|---|
| May 1 | 80°F | 67°F | 79% | 50% |
| May 8 | 80°F | 67°F | 77% | 48% |
| May 15 | 81°F | 67°F | 75% | 47% |
| May 22 | 81°F | 68°F | 76% | 47% |
| May 31 | 81°F | 68°F | 79% | 50% |
Every day of May: normal high, low and chance of precipitation (warmest afternoon May 31, coldest night May 1)
| Day | High | Low | Chance of 0.01 in | Chance of 0.10 in | Daylight |
|---|---|---|---|---|---|
| May 1 | 80°F | 67°F | 79% | 50% | 12 h 50 min |
| May 2 | 80°F | 67°F | 78% | 50% | 12 h 50 min |
| May 3 | 80°F | 67°F | 78% | 50% | 12 h 50 min |
| May 4 | 80°F | 67°F | 78% | 49% | 12 h 50 min |
| May 5 | 80°F | 67°F | 77% | 49% | 12 h 50 min |
| May 6 | 80°F | 67°F | 77% | 49% | 13 h |
| May 7 | 80°F | 67°F | 77% | 48% | 13 h |
| May 8 | 80°F | 67°F | 77% | 48% | 13 h |
| May 9 | 80°F | 67°F | 76% | 48% | 13 h |
| May 10 | 80°F | 67°F | 76% | 47% | 13 h |
| May 11 | 81°F | 67°F | 76% | 47% | 13 h |
| May 12 | 81°F | 67°F | 76% | 47% | 13 h |
| May 13 | 81°F | 67°F | 76% | 47% | 13 h |
| May 14 | 81°F | 67°F | 76% | 47% | 13 h |
| May 15 | 81°F | 67°F | 75% | 47% | 13 h |
| May 16 | 81°F | 67°F | 75% | 47% | 13 h |
| May 17 | 81°F | 67°F | 75% | 47% | 13 h |
| May 18 | 81°F | 67°F | 76% | 47% | 13 h 10 min |
| May 19 | 81°F | 67°F | 76% | 47% | 13 h 10 min |
| May 20 | 81°F | 68°F | 76% | 47% | 13 h 10 min |
| May 21 | 81°F | 68°F | 76% | 47% | 13 h 10 min |
| May 22 | 81°F | 68°F | 76% | 47% | 13 h 10 min |
| May 23 | 81°F | 68°F | 76% | 47% | 13 h 10 min |
| May 24 | 81°F | 68°F | 76% | 47% | 13 h 10 min |
| May 25 | 81°F | 68°F | 77% | 48% | 13 h 10 min |
| May 26 | 81°F | 68°F | 77% | 48% | 13 h 10 min |
| May 27 | 81°F | 68°F | 77% | 48% | 13 h 10 min |
| May 28 | 81°F | 68°F | 78% | 49% | 13 h 10 min |
| May 29 | 81°F | 68°F | 78% | 49% | 13 h 10 min |
| May 30 | 81°F | 68°F | 78% | 49% | 13 h 10 min |
| May 31 | 81°F | 68°F | 79% | 50% | 13 h 10 min |
- Normal high
- 81°FMay average
- Normal low
- 67°FMay average
- Precipitation
- 6.99 inmonth total
- Days with precipitation
- 230.01 inch or more
- Daylight
- 12 h 50 min to 13 h 10 minMay 1 to May 31
- Days at 70°F or more
- 31
- Days at 80°F or more
- 26
- Sunshine
- 72%of clear-sky sunlight (NASA)
Source: NOAA NCEI 1991-2020 daily normals, station USW00021504; monthly normals. Daylight is computed from the place's latitude with NOAA's solar equations.
Does it rain in Hilo in May?
On a given May day the chance of 0.01 inch or more is 77% on average, highest around May 31 (79%). In all, 6.99 in falls on 23 days of a normal May, 1 of them with an inch or more.
Source: NOAA NCEI 1991-2020 daily and monthly normals, station USW00021504.
How humid and windy is Hilo in May?
At 3 p.m. the normal temperature is 80°F with 64% relative humidity and a dew point of 67°F; at 6 a.m. it is 69°F with 84% humidity. The wind averages 6.4 mph, most often from the east-northeast in the afternoon. A dew point of 65°F or more feels muggy to most people.
| Time | Temperature | Dew point | Humidity | Wind | Clear or few clouds |
|---|---|---|---|---|---|
| 6 a.m. | 69°F | 64°F | 84% | 5.5 mph | – |
| 9 a.m. | 77°F | 67°F | 71% | 5.4 mph | 21% |
| noon | 80°F | 67°F | 64% | 9.9 mph | 27% |
| 3 p.m. | 80°F | 67°F | 64% | 10.0 mph | 19% |
| 6 p.m. | 77°F | 67°F | 71% | 6.8 mph | 23% |
| 9 p.m. | 73°F | 68°F | 83% | 4.4 mph | – |
Source: NOAA NCEI 1991-2020 hourly normals, station USW00021504. Hourly normals exist only for NOAA's first-order stations; a dash where NOAA publishes no value for that hour (the sky at some hours).
What are the records for May in Hilo?
The warmest May temperature on Hilo's official record (since 1949) is 94°F, on May 20, 1966; the coldest is 58°F, on May 23, 2024. The wettest May brought 25.01 in (1964).
The May mean against the 1991-2020 normal of 74.0°F: 2022 74.9°F (+0.9), 2023 74.4°F (+0.4), 2024 74.4°F (+0.4), 2025 75.0°F (+1.0), 2026 75.0°F (+1.0). 5 of 5 ran warmer than normal.
| May | Mean | Against normal | Precip. |
|---|---|---|---|
| 2022 | 74.9°F | +0.9°F | 12.65 in |
| 2023 | 74.4°F | +0.4°F | 5.46 in |
| 2024 | 74.4°F | +0.4°F | 9.85 in |
| 2025 | 75.0°F | +1.0°F | 4.51 in |
| 2026 | 75.0°F | +1.0°F | 18.18 in |
Source: records: ACIS, NWS threaded record ITOthr; recent months: ACIS, station USW00021504. Records and recent months use complete months only.
How does May in Hilo compare across Hawaii?
Across the 18 places PlainClimate covers in Hawaii, May normal highs run from 71°F in Kula to 87°F in Kahului; Hilo's is 81°F.
Source: NOAA NCEI 1991-2020 monthly normals for every station in the state.