Kauai Weather by Month: A Complete Guide for Travelers
Kauai has a warm tropical climate throughout the year, with relatively small changes in air temperature from season to season. Based on the weather data provided, average daytime highs range from about 72°F to 77°F, while nighttime lows generally stay between 54°F and 63°F.
Rainfall varies considerably by month. April and July are among the wettest months in the provided data, while September is the driest. Kauai also has plenty of daylight year-round, ranging from about 11 hours in winter to 13.5 hours in June and July.
Ocean temperatures remain comfortable throughout the year, generally ranging from about 75°F to 81°F. Kauai’s warmest ocean water occurs around September and October.
Kauai Weather by Month
You can click the image below to view the full-size weather chart for Kauai island.
January – Warm, Wet and Comfortable
Average high: 72°F (22°C)
Average low: 54°F (12°C)
Rainfall: 6.33 inches (160.9 mm)
Water temperature: 76°F
Daylight: 11 hours
January is a warm but relatively wet month on Kauai. Average daytime temperatures reach around 72°F (22°C), while nighttime temperatures cool to about 54°F (12°C).
Rainfall averages 6.33 inches (160.9 mm), so visitors should be prepared for occasional showers. With around 11 hours of daylight, there is still plenty of time for hiking, sightseeing, and enjoying the island’s beaches.
The ocean remains comfortable at around 76°F, making swimming and water activities possible even during winter.
Best for:
- Hiking and exploring tropical landscapes
- Beach activities without extreme heat
- Waterfalls and lush scenery
- Enjoying Kauai during the winter season
February – Warm Days and Frequent Rain
Average high: 72°F (22°C)
Average low: 54°F (12°C)
Rainfall: 7.40 inches (188 mm)
Water temperature: 75°F
Daylight: 11.5 hours
February has similar temperatures to January, with average highs around 72°F (22°C) and lows near 54°F (12°C).
Rainfall increases to about 7.40 inches (188 mm), making February one of the wetter periods in the provided data. However, rain showers can be intermittent, allowing visitors to enjoy outdoor activities between showers.
Ocean temperatures average around 75°F, which is still comfortable for swimming, snorkeling, and other water activities.
Best for:
- Exploring Kauai’s lush scenery
- Waterfall photography
- Hiking between rain showers
- Swimming and snorkeling
March – Mild, Warm and Increasingly Bright
Average high: 72°F (22°C)
Average low: 55°F (13°C)
Rainfall: 7.67 inches (194.9 mm)
Water temperature: 76°F
Daylight: 12 hours
March remains pleasantly warm, with average highs of about 72°F (22°C) and nighttime lows around 55°F (13°C).
Rainfall averages 7.67 inches (194.9 mm), so wet weather remains common. The longer 12-hour days, however, provide more time for outdoor adventures.
Water temperatures are around 76°F, offering comfortable conditions for swimming and snorkeling.
Best for:
- Longer hiking days
- Exploring scenic viewpoints
- Water activities
- Tropical landscape photography
April – Warm and Very Wet
Average high: 72°F (22°C)
Average low: 57°F (14°C)
Rainfall: 9.80 inches (248.9 mm)
Water temperature: 77°F
Daylight: 12.5 hours
April is one of the wettest months in the provided Kauai data. Average temperatures remain mild, with highs around 72°F (22°C) and lows near 57°F (14°C).
Rainfall reaches about 9.80 inches (248.9 mm), so rain gear is useful for visitors planning hikes or outdoor excursions. The longer 12.5 hours of daylight still provide plenty of opportunities to explore.
The ocean warms to around 77°F, making April a pleasant month for swimming.
Best for:
- Waterfalls and lush vegetation
- Scenic drives
- Hiking with rain protection
- Swimming and snorkeling
May – Warm Days and Long Sunshine Hours
Average high: 73°F (23°C)
Average low: 59°F (15°C)
Rainfall: 9.26 inches (235.3 mm)
Water temperature: 78°F
Daylight: 13 hours
May brings slightly warmer temperatures, with average highs of 73°F (23°C) and lows around 59°F (15°C).
Rainfall remains high at approximately 9.26 inches (235.3 mm), although conditions can vary considerably across the island. Kauai’s long 13-hour days are ideal for fitting several activities into a single day.
Water temperatures rise to around 78°F, creating very comfortable conditions for swimming and snorkeling.
Best for:
- Beach days
- Snorkeling and swimming
- Hiking in lush landscapes
- Long sightseeing days
June – Warm, Wet and Very Long Days
Average high: 73°F (23°C)
Average low: 61°F (16°C)
Rainfall: 7.03 inches (178.6 mm)
Water temperature: 79°F
Daylight: 13.5 hours
June is warm and has some of the longest days of the year on Kauai. Average highs reach about 73°F (23°C), while nighttime temperatures remain around 61°F (16°C).
Rainfall averages 7.03 inches (178.6 mm). Although showers are still possible, the 13.5 hours of daylight provide excellent opportunities for outdoor activities.
The ocean reaches approximately 79°F, making June especially appealing for swimming, snorkeling, kayaking, and other water activities.
Best for:
- Swimming and snorkeling
- Hiking
- Kayaking
- Long outdoor excursions
July – Warm, Humid and Rainy
Average high: 73°F (23°C)
Average low: 61°F (16°C)
Rainfall: 9.44 inches (239.9 mm)
Water temperature: 80°F
Daylight: 13.5 hours
July maintains warm temperatures, with average highs around 73°F (23°C) and lows near 61°F (16°C).
Rainfall increases to approximately 9.44 inches (239.9 mm), making it one of the wetter months in the supplied data. Despite the rainfall, July has 13.5 hours of daylight, giving visitors plenty of time to explore.
Ocean temperatures reach around 80°F, making the water particularly inviting for beach and ocean activities.
Best for:
- Swimming and snorkeling
- Beach activities
- Water sports
- Exploring Kauai’s tropical scenery
August – Warmest Air and Long Days
Average high: 75°F (24°C)
Average low: 63°F (17°C)
Rainfall: 8.00 inches (203.3 mm)
Water temperature: 80°F
Daylight: 13 hours
August is one of the warmest months on Kauai. Average daytime highs reach around 75°F (24°C), while nighttime temperatures remain comfortable at about 63°F (17°C).
Rainfall averages 8.00 inches (203.3 mm), but showers are often part of the island’s tropical climate rather than an all-day occurrence.
The ocean stays around 80°F, making August excellent for swimming, snorkeling, and other water activities.
Best for:
- Beach vacations
- Swimming and snorkeling
- Hiking
- Tropical outdoor adventures
September – Warm, Relatively Dry and Great for Beaches
Average high: 77°F (25°C)
Average low: 61°F (16°C)
Rainfall: 6.11 inches (155.2 mm)
Water temperature: 81°F
Daylight: 12.5 hours
September is the warmest month in the provided Kauai temperature data, with average highs of 77°F (25°C). Nighttime temperatures remain around 61°F (16°C).
Rainfall drops to about 6.11 inches (155.2 mm), the lowest monthly total in the supplied data. With 12.5 hours of daylight, September offers plenty of time for outdoor adventures.
The ocean reaches around 81°F, among the warmest water temperatures of the year.
Best for:
- Beach vacations
- Swimming and snorkeling
- Hiking
- Water sports and ocean activities
October – Warm with Comfortable Ocean Water
Average high: 75°F (24°C)
Average low: 61°F (16°C)
Rainfall: 7.74 inches (196.7 mm)
Water temperature: 81°F
Daylight: 11.5 hours
October remains warm, with average daytime temperatures around 75°F (24°C) and nighttime lows near 61°F (16°C).
Rainfall increases slightly to 7.74 inches (196.7 mm). With 11.5 hours of daylight, visitors still have plenty of time for hiking, sightseeing, and beach activities.
Ocean temperatures remain near their annual peak at approximately 81°F, making October an excellent month for swimming and snorkeling.
Best for:
- Swimming and snorkeling
- Beach activities
- Hiking
- Exploring Kauai’s natural attractions
November – Warm, Wet and Tropical
Average high: 75°F (24°C)
Average low: 59°F (15°C)
Rainfall: 9.40 inches (238.7 mm)
Water temperature: 79°F
Daylight: 11 hours
November brings slightly cooler nights but remains warm during the day. Average highs reach about 75°F (24°C), while lows fall to around 59°F (15°C).
Rainfall rises to approximately 9.40 inches (238.7 mm), making November one of the wetter months in the supplied data. Visitors should expect tropical showers but can still enjoy plenty of outdoor activities.
The ocean remains warm at around 79°F.
Best for:
- Waterfalls and lush scenery
- Hiking between showers
- Swimming
- Tropical photography
December – Warm and Wet with Shorter Days
Average high: 73°F (23°C)
Average low: 55°F (13°C)
Rainfall: 6.39 inches (162.4 mm)
Water temperature: 78°F
Daylight: 11 hours
December remains pleasantly warm compared with winter destinations elsewhere. Average highs are around 73°F (23°C), while nighttime temperatures fall to about 55°F (13°C).
Rainfall averages 6.39 inches (162.4 mm), and the island receives around 11 hours of daylight.
The ocean stays comfortable at approximately 78°F, so visitors can enjoy swimming and other water activities even during the winter season.
Best for:
- Winter beach vacations
- Swimming and snorkeling
- Hiking in mild temperatures
- Enjoying Kauai’s tropical landscapes
Kauai Water Temperature by Month
| Month | Avg High °F (°C) | Avg Low °F (°C) | Rainfall (inches) | Water Temperature | Daylight (hours) |
|---|---|---|---|---|---|
| January | 72°F (22°C) | 54°F (12°C) | 6.33 | 76°F | 11 |
| February | 72°F (22°C) | 54°F (12°C) | 7.40 | 75°F | 11.5 |
| March | 72°F (22°C) | 55°F (13°C) | 7.67 | 76°F | 12 |
| April | 72°F (22°C) | 57°F (14°C) | 9.80 | 77°F | 12.5 |
| May | 73°F (23°C) | 59°F (15°C) | 9.26 | 78°F | 13 |
| June | 73°F (23°C) | 61°F (16°C) | 7.03 | 79°F | 13.5 |
| July | 73°F (23°C) | 61°F (16°C) | 9.44 | 80°F | 13.5 |
| August | 75°F (24°C) | 63°F (17°C) | 8.00 | 80°F | 13 |
| September | 77°F (25°C) | 61°F (16°C) | 6.11 | 81°F | 12.5 |
| October | 75°F (24°C) | 61°F (16°C) | 7.74 | 81°F | 11.5 |
| November | 75°F (24°C) | 59°F (15°C) | 9.40 | 79°F | 11 |
| December | 73°F (23°C) | 55°F (13°C) | 6.39 | 78°F | 11 |
FAQs about Kauai Weather
1. What is the weather like in Kauai year-round?
Kauai has a warm tropical climate throughout the year, with average highs generally ranging from 72°F to 77°F and relatively mild nighttime temperatures.
2. What is the best month to visit Kauai for good weather?
September is one of the best months for warm and relatively dry weather based on the provided data. It has an average high of 77°F, around 6.11 inches of rainfall, and 12.5 hours of daylight.
3. What is the hottest month in Kauai?
September is the warmest month in the provided data, with an average high of 77°F and an average low of 61°F.
4. What is the coldest month in Kauai?
January and February have some of the coolest temperatures, with average lows of 54°F and highs around 72°F.
5. Does Kauai get cold in winter?
Kauai does not usually experience extreme winter cold. January and February have average highs around 72°F and lows around 54°F, making winter relatively mild.
6. Does it rain a lot in Kauai?
Yes. Rainfall varies considerably throughout the year, with some months receiving more than 9 inches. April, May, July, and November are among the wetter months in the provided data.
7. What is the rainiest month in Kauai?
April is the wettest month in the provided data, with approximately 9.80 inches of rainfall.
8. What is the driest month in Kauai?
September is the driest month in the provided data, receiving approximately 6.11 inches of rainfall.
9. Does it rain all day in Kauai?
Not necessarily. Kauai can experience short tropical showers followed by periods of sunshine. Rainfall totals do not mean that it rains continuously throughout the day.
10. What is the average temperature in Kauai in summer?
Summer temperatures are warm but generally comfortable. Average highs range from about 73°F in June and July to 75°F in August, while lows range from 61°F to 63°F.
11. What is Kauai weather like in winter?
Winter is warm compared with many other destinations. January and February have average highs of about 72°F and lows around 54°F, although rainfall can be relatively high.
12. What is the best month for swimming in Kauai?
September and October are excellent months for swimming because ocean temperatures reach about 81°F, among the warmest of the year.
13. What is the water temperature in Kauai?
Ocean temperatures generally range from about 75°F to 81°F throughout the year. The warmest water occurs around September and October.
14. Is Kauai warm enough to swim in January?
Yes. The ocean temperature is around 76°F in January, which is comfortable for many visitors. Air temperatures are also mild, with an average high of 72°F.
15. What month has the most daylight in Kauai?
June and July have the longest days, with approximately 13.5 hours of daylight.
16. How many hours of daylight does Kauai get in winter?
Kauai receives about 11 hours of daylight in January, February, November, and December.
17. Is August a good month to visit Kauai?
Yes. August is warm, with an average high of 75°F, an average low of 63°F, and about 13 hours of daylight. The ocean is around 80°F.
18. Is September a good month to visit Kauai?
September is an excellent choice for warm-weather activities. It has the highest average temperature in the provided data, relatively low rainfall, and an ocean temperature of about 81°F.
19. Is November a rainy month in Kauai?
November can be quite wet, with approximately 9.40 inches of rainfall in the provided data. However, temperatures remain warm, with an average high of 75°F.
20. What is the best time of year for outdoor activities in Kauai?
The best time depends on the activity, but late spring through early fall generally offers warm temperatures, long daylight hours, and comfortable ocean temperatures. September stands out for its combination of warm weather, relatively lower rainfall, and warm ocean water.
Final Thoughts
Kauai is a year-round destination with something special to offer every month. Whether you’re chasing sunshine, surfing giant waves, or exploring lush valleys, understanding Kauai’s monthly weather patterns will help you plan the perfect trip. Choose the season that matches your travel style, and you’ll experience the magic of the Garden Isle at its best.
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