Ko Olina has some of the mildest winter nights among U.S. towns
Sunny July days climb to about 88°. By precipitation alone, it ranks drier than 94% of U.S. towns. Temperatures cover 24° across the year, low to high. Plan time outside from December to April, when highs sit at 81–84°.
A year in Ko Olina at a glance
Each month’s typical high and low, and what it brings.
What stands out about Ko Olina’s climate
Compared with towns across the U.S., with Ko Olina’s place in Hawaii beside it.
What a year in Ko Olina feels like
Typical highs and lows by season and by month, from NOAA’s 30-year normals.
Frost is rare
Frost and day counts come from NOAA’s station at Ewa Kalaeloa Airport, 4 miles from the town’s center, at about the same height.
The 2023 USDA map puts Ko Olina’s center in zone 12b: the coldest night of a typical winter, averaged over 1991–2020, reaches about 56°. Plant labels use the zone; frost dates tell you when to plant.
90° days by month
Average days at 90° or more
About 14 inches of rain a year
December is the wettest month and June the driest. Rain falls on about 214 days a year. Snow is rare: about 0.0" in a normal year at Aiea Hts 764.6, HI, so most winters see none.
Rain + melted snow by month
Inches of water
Heating and cooling a home in Ko Olina
0% of the work is heating, so air conditioning is the bigger bill. No month averages under 55°.
Degree days add up how far each day’s average falls below (heating) or rises above (cooling) 65° over a year. NOAA normals at Ewa Kalaeloa Airport.
Living with Ko Olina’s climate
What the numbers mean for a garden, a free afternoon and a bad-weather day.
Zone 12b. Frost almost never comes, so tender plants can often stay out through winter.
Months with highs of 62–84° and lows of 40° or more: January, February, March, April and December. 1.9 miles of trails are waiting.
Parks & trails →Of the yearly building losses FEMA expects in Ko Olina from natural hazards, river flooding is the largest share (41%). Normals are averages; the hazards page covers the extremes.
Natural hazards →Ko Olina and similar climates
TownRatings has no climate map of the towns around Ko Olina yet.
Climates most like Ko Olina’s, farther away
TownRatings’ own comparison of NOAA 1991–2020 normals, not a NOAA product: places of 5,000+ at least 150 miles away, one per state, closest on January low, July high, precipitation and snow.
| Town | Jan. low | July high | Precip. | Snow |
|---|---|---|---|---|
| Ko Olina, HI | 65° | 88° | 14" | 0.0" |
| Hacienda Heights, CA | 47° | 87° | 14" | 0.0" |
| Port Isabel, TX | 52° | 92° | 26" | 0.2" |
| Key West, FL | 65° | 90° | 42" | 0.0" |
| Corona de Tucson, AZ | 36° | 96° | 14" | 0.1" |
Temperatures and precipitation come from NOAA’s 5 km grid; snow and day counts from the stations named on this page.
How Ko Olina compares
Against 12,954 U.S. towns of 2,500 or more (one per 5 km climate cell), with Ko Olina’s place among Hawaii’s.
Ko Olina weather by month
Highs, lows and precipitation from the nearest NOAA station; snow, wet days and snow on the ground from Aiea Hts 764.6, HI. 1991–2020 normals.
| Month | High | Low | Rain + melt | Snow | Wet days | Snow on ground |
|---|---|---|---|---|---|---|
| January | 81° | 65° | 1.4" | 0.0" | 13 | 0 |
| February | 81° | 65° | 1.8" | 0.0" | 13 | 0 |
| March | 82° | 66° | 2.0" | 0.0" | 16 | 0 |
| April | 84° | 68° | 0.6" | 0.0" | 19 | 0 |
| May | 85° | 69° | 1.0" | 0.0" | 17 | 0 |
| June | 87° | 71° | 0.3" | 0.0" | 20 | 0 |
| July | 88° | 73° | 0.3" | 0.0" | 21 | 0 |
| August | 89° | 73° | 0.6" | 0.0" | 19 | 0 |
| September | 89° | 72° | 0.7" | 0.0" | 18 | 0 |
| October | 87° | 72° | 1.3" | 0.0" | 20 | 0 |
| November | 84° | 69° | 1.8" | 0.0" | 20 | 0 |
| December | 82° | 67° | 2.3" | 0.0" | 18 | 0 |
| Year | 85° | 69° | 13.9" | 0.0" | 214 | 0 |
Where Ko Olina’s numbers come from
Normals are 30-year averages, not a forecast. How TownRatings reads climate data →
- Temperatures and precipitation: NOAA’s 1991–2020 normals at the nearest station (NOAA’s grid doesn’t cover Hawaii).
- Snow: Aiea Hts 764.6, HI.
- Frost, freezing nights, 90° and 100° days, heating and cooling: Ewa Kalaeloa Airport, 4 miles from the town’s center, at about the same height; the nearest station that passes our checks for distance, height and agreement with the grid.
- Growing zone: USDA Plant Hardiness Zone Map, 2023. USDA Agricultural Research Service and PRISM Group, Oregon State University, prism.oregonstate.edu/phzm, accessed 8 Oct 2026.
- Storms and extremes: FEMA National Risk Index (expected annual losses to buildings).
Common questions about Ko Olina’s climate
What is the weather like in Ko Olina?
A typical July afternoon reaches 88°, a January night drops to 65°, and snow is almost unheard of. Milder January nights than all but 42 U.S. towns; hotter July afternoons than 67% of U.S. towns.
How cold does it get in Ko Olina in winter?
January nights average 65°. A night at 32° or below comes in only some winters (0.0 a year on average).
How much snow does Ko Olina get?
About 0.0 inches in a normal winter at Aiea Hts 764.6, HI, so most winters see none.
How hot does it get in Ko Olina?
July, with a typical high of 88° and a low of 73°. About 31 days a year reach 90° (Ewa Kalaeloa Airport).
When is the first and last frost in Ko Olina?
Most years have no frost at all: a 32° night comes in about 0% of winters at Ewa Kalaeloa Airport, usually in December or January.
What growing zone is Ko Olina in?
Zone 12b on the 2023 USDA Plant Hardiness Zone Map: the coldest night of a typical winter reaches about 56°.
What is the best time of year to visit Ko Olina?
By one simple rule (highs of 62–84° and lows of 40° or more), January, February, March, April and December. The rule is ours, not NOAA’s; the month table has the numbers to judge by.
Neighbors talk weather
Gardens, snow, and the best days of the year in Ko Olina.
Source: NOAA NCEI U.S. Climate Normals, 1991–2020; USDA/PRISM 2023 hardiness zones; FEMA National Risk Index. Today’s forecast: National Weather Service.