Kona (Big Island) in September

In September, Kona (Big Island) averages 27°C (81°F) during the day and 23°C (73°F) at night, with frequent rain — about 27 days of the month see precipitation (206 mm total).

Off-peak

Conditions are warm and beach-friendly. Expect daily rain or showers, often in heavy bursts.

It's peak hurricane season in Kona (Big Island) during September. Travel is possible but expect storm risk, possible flight disruption, and generally lower travel insurance coverage.

27°C
Avg high
23°C
Avg low
27
Rain days
206 mm
Rainfall

How September compares to the rest of the year in Kona (Big Island)

1st
warmest month of the 12
6th
wettest month of the 12
9%
of yearly rainfall falls in September
12 h 15 min
daylight on the 15th

September is one of the warmest months in Kona (Big Island) (1st of 12) and moderately rainy compared to the rest of the year (6th of 12). Daytime temperature runs 1°C above the annual average (26°C). September runs roughly the same as August (27°C) and stays flat into October.

September sunrise & sunset in Kona (Big Island)

🌅
Sunrise (15th)
6:11 AM
🌇
Sunset (15th)
6:26 PM
Day length
12 h 15 min

Times shown for Kona (Big Island) local time (Pacific/Honolulu), calculated for the 15th of September. They shift by a few minutes day to day across the month.

Photography light in Kona (Big Island) — September

Golden-hour and blue-hour windows for the 15th of September, in Kona (Big Island)'s local time. Use these for soft warm light (golden) or cool architectural twilight (blue).

🌅 Blue hour (AM)
5:11 AM – 5:51 AM
🌄 Golden hour (AM)
5:51 AM – 6:51 AM
🌇 Golden hour (PM)
5:46 PM – 6:46 PM
🌆 Blue hour (PM)
6:46 PM – 7:26 PM
Milky Way galactic core
Fair
Core only briefly above the horizon — a marginal month even from dark sites near Kona (Big Island).

📅 When to book — Kona (Big Island) in September

Travel writers usually only tell you when to go. Here's when to book flights and lodging for the best mix of price and availability, based on September's tier (Off-peak) and Kona (Big Island)'s popularity.

✈ Flights — lead time
3-6 weeks
Cheapest flights of the year. Last-minute deals are real if you can be flexible. ⚠ Peak hazard season — book flexible-change tickets and travel insurance with weather-disruption coverage.
🏨 Lodging — lead time
2-4 weeks
Last-minute bookings work fine. Some seasonal properties close — call ahead if it's a small boutique or beach resort.

Crowds & pricing — September in Kona (Big Island)

Off-peak

This is off-peak for Kona (Big Island) — the lowest prices of the year and the fewest crowds, but with real trade-offs: some restaurants, hotels, and beach businesses may close for the season; weather conditions can make outdoor activities unpredictable; and a handful of seasonal sights run reduced hours or close entirely. Great if you prefer a quiet local rhythm and don't mind the climate giving you reasons to choose indoor activities.

Why this tier: peak hazard season (2 active)

Sun & mosquito risk — September in Kona (Big Island)

☀️ UV Index (noon, 15th)
12.2
Extreme
Stay indoors during midday hours; SPF 50+ even briefly outside, UPF clothing, wide-brim hat, sunglasses essential.
🦟 Mosquito risk
●●●●●
Severe
Severe mosquito season with active disease transmission risk. DEET 30%+, picaridin 20%, long sleeves day and night, treated nets, and check CDC/WHO travel advisories before going.

UV is a clear-sky sea-level estimate — clouds, altitude, and reflective surfaces (snow, water) shift it ±30%. Mosquito risk is climate-derived only; for current disease advisories (dengue, malaria, zika) check the CDC or WHO travel pages before your trip.

Sea temperature in Kona (Big Island) — September

27.3°C (81°F)
bath-warm
tropical and comfortable for hours

Across the year Kona (Big Island)'s sea swings from 25°C (March) to 27.3°C (September) — September sits at 27.3°C.

Kona (Big Island) in other months

MonthAvg highAvg lowRainfallRain daysSnow days
January 25°C / 76°F 19°C / 67°F 97 mm 23
February 25°C / 76°F 19°C / 67°F 118 mm 22
March 25°C / 77°F 20°C / 68°F 111 mm 23
April 25°C / 77°F 21°C / 69°F 207 mm 27
May 26°C / 78°F 21°C / 70°F 224 mm 28
June 26°C / 79°F 22°C / 71°F 301 mm 29
July 27°C / 81°F 23°C / 73°F 296 mm 30
August 27°C / 81°F 23°C / 73°F 278 mm 29
September 27°C / 81°F 23°C / 73°F 206 mm 27
October 27°C / 81°F 22°C / 72°F 138 mm 25
November 26°C / 80°F 21°C / 70°F 103 mm 22
December 25°C / 77°F 20°C / 68°F 134 mm 23

Other cities with similar September weather

🌍 See the full ranked list of climate twins for Kona (Big Island) in September →

Frequently asked questions

How hot is Kona (Big Island) in September?

In September, Kona (Big Island) averages a high of 27°C (81°F) and a low of 23°C (73°F) — generally warm.

Does it rain a lot in Kona (Big Island) in September?

September is quite rainy in Kona (Big Island), with about 27 rainy days on average.

Is September a good time to visit Kona (Big Island)?

September is warm but on the rainy side. It suits travelers who are comfortable with warm weather; check the month-by-month ranking to compare it against the rest of the year.

What should I pack for Kona (Big Island) in September?

Pack lightweight, breathable clothing, sunglasses and sunscreen, plus a compact umbrella or rain jacket. See the full September packing list for Kona (Big Island) for a complete, climate-based checklist.

Open Kona (Big Island) on the interactive map

Check the live 10-day forecast and sunrise/sunset.