Question 1

When is the rainy season in Honolulu?

Accepted Answer

Honolulu's rainy season runs through the cooler winter half of the year, roughly **November to April**, when the city collects the bulk of its annual rainfall. In 2025, this wet-season stretch delivered about 388 mm (15.3 inches) of rain — nearly 64% of Honolulu's full-year total of 606 mm (23.9 inches).

The wettest months in 2025 were clustered around winter:

- **January:** 89.5 mm (3.52 inches)
- **December:** 87.8 mm (3.46 inches)
- **April:** 86.5 mm (3.41 inches)

By contrast, the dry season from May to October stayed notably lighter, totaling just 219 mm (8.6 inches). **August** was the driest month of 2025 in Honolulu, with only 24.5 mm (0.96 inches) of rain.

It's worth noting that even Honolulu's "rainy season" is mild by tropical standards. Showers tend to be brief and often pass quickly, and warmth holds steady year-round — monthly average temperatures stayed near 21–25°C (70–77°F) throughout 2025, averaging 23.0°C (73.3°F).

For trip planning, the May-to-October window offers the most reliable dry, sunny conditions in Honolulu, making it ideal for beach days and outdoor activities. Winter visitors should simply pack a light rain layer and expect occasional passing showers rather than washouts.

Question 2

What is the sunniest time of year in Honolulu?

Accepted Answer

The sunniest time of year in Honolulu falls in late spring and early summer, with **May 2025** standing out as the brightest month of the year at 309.6 hours of sunshine — about 10.0 hours per day.

Across the full 2025 calendar year, Honolulu recorded roughly 3,020.9 hours of sunshine, averaging about 8.3 hours of sun per day. After May, the next sunniest months were June (269.2 hours) and October (269.0 hours), so the stretch from May through October offers consistently bright skies. The cloudiest months were February (203.2 hours), December (209.4 hours), and November (228.2 hours), reflecting Honolulu's wetter winter pattern.

The abundant sunshine pairs with warm, stable temperatures. May 2025 averaged 23.0°C (73.4°F), while the sunny mid-year months climbed to monthly means of 23.8–24.7°C (74.8–76.5°F). May also stayed relatively dry, recording just 46.8 mm (1.84 in) of rainfall.

For visitors, this means the best window for sun-focused activities in Honolulu runs from late spring into early autumn. May in particular combines peak sunshine with comfortable temperatures and modest rain, making it an excellent month for beach days, snorkeling, and outdoor sightseeing before the brighter but slightly warmer summer sets in.

Question 3

What is the annual temperature range in Honolulu?

Accepted Answer

Honolulu has one of the most stable year-round climates of any major U.S. city, with monthly average temperatures shifting just 3.6°C (6.5°F) across all of 2025. The annual mean temperature in 2025 was 23.0°C (73.3°F), confirming Honolulu's reputation for consistent, mild warmth.

The warmest stretch came in August 2025, when the monthly average reached 24.7°C (76.5°F). The coolest month was February 2025, averaging 21.1°C (70.0°F). That narrow gap between the hottest and coolest months is what gives Honolulu its famously even climate.

Looking at daily extremes across 2025:

- **Average daily high:** 27.5°C (81.5°F)
- **Average daily low:** 18.3°C (65.0°F)
- **Warmest peak:** 29.8°C (85.6°F) in August 2025
- **Coolest dip:** 14.3°C (57.7°F) in January 2025

Even the most extreme readings stayed comfortable, with daytime highs rarely pushing past 30°C (86°F) and overnight lows almost never approaching cold.

For visitors and residents, this small temperature range means Honolulu rarely requires seasonal wardrobe changes — lightweight clothing works nearly all year. Whether you travel in winter or summer, you can expect daytime warmth in the high 20s°C (low 80s°F) and pleasant evenings. This predictability makes Honolulu an excellent destination in any month of 2025, with no harsh heat waves or cold snaps to plan around.

Question 4

What are the windiest months in Honolulu?

Accepted Answer

The windiest months in Honolulu are during the summer, with July topping the list in 2025 at an average wind speed of 21.2 km/h (13.2 mph). This is when the Pacific trade winds that shape Honolulu's climate are at their strongest and steadiest.

Across the meteorological summer of 2025 (June to August), winds averaged 20.1 km/h (12.5 mph), and the breezy stretch actually began in May, which recorded 20.9 km/h (13.0 mph). For the full 2025 calendar year, Honolulu's average wind speed was a moderate 16.6 km/h (10.3 mph), reflecting the city's reliably ventilated, ocean-influenced conditions.

The calmest period came in winter: February 2025 was the least windy month at just 8.9 km/h (5.5 mph), with the January–February average sitting at 11.8 km/h (7.3 mph). Wind speeds gradually picked up through spring before peaking in midsummer.

For visitors and residents, these steady summer trade winds are a welcome feature rather than a nuisance. They temper Honolulu's warm summer temperatures and high humidity, making beach days, sailing, and windsurfing especially enjoyable from May through August. If you prefer notably calmer air, the winter months of January and February offer the gentlest breezes of the year, though they also bring more rain.

Question 5

How humid is Honolulu throughout the year?

Accepted Answer

Honolulu is consistently humid all year, averaging **76.9% relative humidity** across 2025 with only modest seasonal swings between roughly 74% and 81%.

The most humid month in Honolulu was December 2025 at **81.1%**, followed closely by the winter months of January (78.8%) and February 2025 (80.4%). Humidity eased during the summer, reaching its annual low of **73.7% in June 2025**, with the June–August period averaging about 74.5%. Overall, four months of 2025 sat at or above 78% humidity, all of them in the cooler half of the year.

These humidity levels pair with steady warmth, as Honolulu's mean temperature held near **23.0°C (73.3°F)** throughout 2025. Stronger trade winds in summer (around 19–21 km/h, or 12–13 mph) help offset the moisture, so the drier months of May through September often feel more comfortable despite the heat.

For visitors, this means Honolulu rarely feels dry: expect a humid, tropical climate year-round, with the muggiest, stickiest conditions in December and the most breeze-aided relief during the summer. Lightweight, breathable clothing is a smart choice in Honolulu in any season.

Kalihi Valley

Hawaii

FAQ

When is the rainy season in Honolulu?

What is the sunniest time of year in Honolulu?

What is the annual temperature range in Honolulu?

What are the windiest months in Honolulu?

How humid is Honolulu throughout the year?