Climate and monthly weather forecastHanalei, HI

Climate and monthly weather forecast
The climate of Hanalei
Known for a predominantly tropical climate, Hanalei, Hawaii, USA, is classified as Af according to the Köppen climate classification. This suggests a tropical rainforest climate, with a significant amount of rainfall occurring throughout the year. Geographically located in northern of Kauai island, Hanalei's climate can be characterized by hot summers and mild winters.Moving on to the weather parameters outlined, yearly temperature highs in Hanalei fluctuate from 73.2°F (22.9°C) to 79.7°F (26.5°C), while the lows register between 68.5°F (20.3°C) and 75.9°F (24.4°C). It's worth noting that the relative humidity is rather high, ranging from 75 to 77%, contributing to a rather moist environment. Rainfall is prevalent, observed in a high frequency of days throughout the year -- from 12.5 to 21.1 days per month. Monthly rainfall figures vary between 1.3" (33mm) and 2.52" (64mm).
Observers will note that the sea surface temperature is generally warm, from 75°F (23.9°C) to 81°F (27.2°C). Meanwhile, daylight ranges from 10.8 hours to 13.5 hours, offering extended periods of sunlight particularly during the mid-year. Sunshine hours maintain a similar trend, from 6.2 hours to 9.7 hours.
The best time to visit Hanalei
While weather preferences are to a large extent individual, visitors seeking the highest temperatures and most sunlight might target the period from June to September. During this period, the temperatures scale towards the upper end, from 78.3°F (25.7°C) to 79.7°F (26.5°C). The sunlight is also at its peak with 13.2 to 13.5 hours of daylight, and sunshine ranging from 8.4 to 9.7 hours.The worst time to visit Hanalei
Considering periods of increased rainfall and lower temperatures, the initial months of the year may be less appealing for some travellers. From February to April, rainfall is highest, reaching up to 2.52" (64mm), and the number of rainfall days extends to 18.6 days a month. This period also coincides with relatively lower temperatures varying from 68.5°F (20.3°C) to 70.9°F (21.6°C).Spring weather in Hanalei
Notably warmer than winter, the spring months in Hanalei experience temperature highs oscillating from 73.2°F (22.9°C) in March to 76.8°F (24.9°C) in May. The temperature lows during this period range between 68.9°F (20.5°C) and 72.1°F (22.3°C). While daylight extends from 12 hours in March to 13.2 hours in May, rain remains a constant companion with a frequency of 18.3 to 18.5 days a month and accumulated rainfall from 1.3" (33mm) to 1.57" (40mm).Summer weather in Hanalei
The heralding of summer in Hanalei conveys higher temperature ranges from 78.3°F (25.7°C) in June to a peak of 79.7°F (26.5°C) in September, while the lows fluctuate between 73.9°F (23.3°C) and 75.9°F (24.4°C). Although rainfall persists, the volume decreases slightly to between 1.77" (45mm) and 1.85" (47mm). Importantly, daylight extends to its yearly maximum of up to 13.5 hours with longer sunshine hours of up to 9.7 hours in June.Autumn weather in Hanalei
Autumn in Hanalei ushers in a mild decrease in temperatures, with highs of 79.5°F (26.4°C) in October to 77.2°F (25.1°C) in November. The lows during this period rest at a range from 75.4°F (24.1°C) to 74.1°F (23.4°C). Rainfall shows a marked increase reaching 2.05" (52mm) both in October and November, with up to 19.2 rainy days in November.Winter weather in Hanalei
Winter is relatively mild in Hanalei with highest temperatures ranging from 77.2°F (25.1°C) in December to 73.2°F (22.9°C) in February. Low temperatures follow a similar trend hovering from 71.8°F (22.1°C) to 68.5°F (20.3°C). The prominent feature of winter is the increase in rainfall, escalating to 2.2" (56mm) in December and the number of rainy days reaching up to 18.1 in the same month.Weather in January
The first month of the year in Hanalei, Hawaii, opens with stable and mild weather conditions. It follows closely on the heels of December, offering relatively similar weather features. A bit more sunlight could be enjoyed during the day with an average of 11 hours of daylight. Weather in January »Weather in February
February becomes a bridge between the relatively cooler weather in January and a warmer March in Hanalei. The days become longer and, along with witnessing more daylight, residents see a marginal increase in rainfall to 1.81" (46mm) that adds to the humidity. Weather in February »Weather in March
March signals the arrival of spring in Hanalei, marking a noticeable increase in average temperatures and offering longer daylight hours. Along with longer hours of sunshine, the weather routine sees a more substantial difference in rainfall, peaking at 2.52" (64mm). Weather in March »Weather in April
The weather in April holds a unique place in Hanalei's calendar as it fuses the onset of spring with the prelude to summer. The weather pattern from March continues, albeit with diminished rainfall levels. Headlining the month is the significant increase in daylight hours, up to 12.7, paving the way for more sun-soaked days. Weather in April »Weather in May
May ushers in the summer season, bringing with it the warmest temperatures Hanalei sees all year. The standout feature in May's weather is an increase in both daytime temperatures to 76.8°F (24.9°C) and sea temperature to 77°F (25°C). Weather in May »Weather in June
Hanalei's weather in June serves as an archetypical representation of tropical summer, following the warming trend that starts in May. On average, Hanalei enjoys longest daylight hours compared to other months. Pressure drops slightly from 30.05" (763mm) in May to 30.04" (763mm) in June, hinting at the approaching rainy season. Weather in June »Weather in July
July starts off subtly with a slight dip in sunshine hours from June's high, while marking the advent of the warmest month of the year in Hanalei. The conspicuous feature of July's weather is the temperature, peaking at 79°F (26.1°C). Weather in July »Weather in August
As August arrives in Hanalei, a discernible weather transition takes place, highlighted primarily by the rise in relative humidity up to 77%. Alongside this, the weather characterization sees both the highest sea temperatures and highest maximum temperatures of 79.7°F (26.5°C). Weather in August »Weather in September
September is known in Hanalei for signaling the outset of autumn marking a decrease in both soaring temperatures and high rainfall levels from August. Slightly cooler temperatures and reduced rainfall, coupled with consistent sea temperatures at 81°F (27.2°C), render September conducive for beach activities. Weather in September »Weather in October
October offers Hanalei residents a welcome respite from the September heat, setting the stage for cooler weather as the year continues its course. The key indicator of October's weather transformation is a decline in the daily amount of sunshine to 8.4 hours. Weather in October »Weather in November
Things become more balanced in November, as Hanalei begins to transition into the cooler winter season. November's weather is characterized by a slight drop in both daytime and sea temperatures. The gradual decline in temperature, together with the higher rainfall of 2.05" (52mm) in comparison to October, makes November a relatively cooler harbinger of the coming colder December. The transition into November in Hanalei reveals an average high-temperature of a still moderately hot 77.2°F (25.1°C), mirroring a close resemblance to October. Weather in November »Weather in December
By the time December rolls around, the weather in Hanalei has turned noticeably cooler, with the year happily ending on a pleasant note. Featuring the shortest daylight hours of the year at 10.8, the sea temperatures also fall back to 77°F (25°C). Weather in December »Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature
Hanalei, HI
The warmest month (with the highest average high temperature) is September (79.7°F).
The months with the lowest average high temperature are February and March (73.2°F).
The month with the highest average low temperature is September (75.9°F).
The coldest month (with the lowest average low temperature) is February (68.5°F).
Average pressure
Hanalei, HI
- Average pressure in January:
30.01"Hg - Average pressure in February:
30.02"Hg - Average pressure in March:
30.06"Hg - Average pressure in April:
30.07"Hg - Average pressure in May:
30.05"Hg - Average pressure in June:
30.04"Hg
- Average pressure in July:
30.02"Hg - Average pressure in August:
30"Hg - Average pressure in September:
29.98"Hg - Average pressure in October:
29.98"Hg - Average pressure in November:
30.01"Hg - Average pressure in December:
30.01"Hg
The month with the highest atmospheric pressure is April (30.07"Hg).
The months with the lowest atmospheric pressure are September and October (29.98"Hg).
Average wind speed
Hanalei, HI
- Average wind speed in January:
10mph - Average wind speed in February:
11.1mph - Average wind speed in March:
12mph - Average wind speed in April:
11.5mph - Average wind speed in May:
10.5mph - Average wind speed in June:
12.1mph
- Average wind speed in July:
12.3mph - Average wind speed in August:
12.1mph - Average wind speed in September:
11.1mph - Average wind speed in October:
10.5mph - Average wind speed in November:
12.1mph - Average wind speed in December:
11.2mph
The windiest month (with the highest average wind speed) is July (12.3mph).
The calmest month (with the lowest average wind speed) is January (10mph).
Average humidity
Hanalei, HI
The months with the highest relative humidity are June, July, August, October and December (77%).
The month with the lowest relative humidity is January (75%).
Average rainfall
Hanalei, HI
- Average rainfall in January:
1.57" - Average rainfall in February:
1.81" - Average rainfall in March:
2.52" - Average rainfall in April:
1.3" - Average rainfall in May:
1.57" - Average rainfall in June:
1.85"
- Average rainfall in July:
1.77" - Average rainfall in August:
1.89" - Average rainfall in September:
1.54" - Average rainfall in October:
2.05" - Average rainfall in November:
2.05" - Average rainfall in December:
2.2"
The wettest month (with the highest rainfall) is March (2.52").
The driest month (with the least rainfall) is April (1.3").
Average rainfall days
Hanalei, HI
- Average rainfall days in January:
12.5 days - Average rainfall days in February:
15 days - Average rainfall days in March:
18.6 days - Average rainfall days in April:
18.3 days - Average rainfall days in May:
18.5 days - Average rainfall days in June:
18.8 days
- Average rainfall days in July:
20.9 days - Average rainfall days in August:
21.1 days - Average rainfall days in September:
18.7 days - Average rainfall days in October:
18.7 days - Average rainfall days in November:
19.2 days - Average rainfall days in December:
18.1 days
The month with the highest number of rainy days is August (21.1 days).
The month with the least rainy days is January (12.5 days).
Average sea temperature
Hanalei, HI
The best months for swimming (with the highest average sea temperature) are September and October (81°F).
The coldest months (with the lowest average sea temperature) are January, February, March and April (75°F).
Average daylight / Average sunshine
Hanalei, HI
- Average daylight in January:
11h and 0min - Average daylight in February:
11h and 24min - Average daylight in March:
12h and 0min - Average daylight in April:
12h and 42min - Average daylight in May:
13h and 12min - Average daylight in June:
13h and 30min
- Average daylight in July:
13h and 18min - Average daylight in August:
12h and 54min - Average daylight in September:
12h and 18min - Average daylight in October:
11h and 36min - Average daylight in November:
11h and 6min - Average daylight in December:
10h and 48min
The month with the longest days is June (Average daylight: 13h and 30min).
The month with the shortest days is December (Average daylight: 10h and 48min).
- Average sunshine in January:
8h and 6min - Average sunshine in February:
7h and 42min - Average sunshine in March:
7h and 30min - Average sunshine in April:
7h and 48min - Average sunshine in May:
9h and 18min - Average sunshine in June:
9h and 42min
- Average sunshine in July:
8h and 36min - Average sunshine in August:
8h and 24min - Average sunshine in September:
8h and 42min - Average sunshine in October:
8h and 24min - Average sunshine in November:
6h and 12min - Average sunshine in December:
6h and 24min
The month with the most sunshine is June (Average sunshine: 9h and 42min).
The month with the least sunshine is November (Average sunshine: 6h and 12min).
Average sunshine days
Hanalei, HI
- Average sunshine days in January:
12.8 days - Average sunshine days in February:
7.8 days - Average sunshine days in March:
6.3 days - Average sunshine days in April:
5.7 days - Average sunshine days in May:
6.7 days - Average sunshine days in June:
5 days
- Average sunshine days in July:
3.9 days - Average sunshine days in August:
2.9 days - Average sunshine days in September:
5.3 days - Average sunshine days in October:
6.3 days - Average sunshine days in November:
4.7 days - Average sunshine days in December:
6.7 days
The month with the most sunshine days is January (12.8 days).
The month with the least sunshine days is August (2.9 days).
Average UV index
Hanalei, HI
The month with the highest UV index is September (UV index 7).
The months with the lowest UV index are January, February, March, April, May, June, July, August, October, November and December (UV index 6).
Average cloud cover
Hanalei, HI
The month with the most cloud cover is March (Cloud cover 47).
The months with the least cloud cover are January and September (Cloud cover 38).
Average visibility
Hanalei, HI
The months with the highest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).
The months with the lowest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).





