ホノルルの月別の天気

Honolulu has a moderate warm to hot climate, with very little change of temperature throughout the year — the average high is 80-90°F (27-32°C) and the average low is 65-75°F (19-24°C) any time of the year. The summer months do see some humidity alongside the heat, with typical heat indices in the late summer averaging around during the day and at night. Heat indices seldom rise above , though there are a few nights where heat indices don't go below in the late summer. Water temperature averages 82°F (27°C) in the summer months and 77°F (25°C) in the winter months. Daylight hours also do not see any significant variation either, with sunrises and sunsets occurring at 5:50AM and 7:15PM in the summer months, and 7:10AM and 5:50PM in the winter months. The only noticeable variation in seasons is in terms of rainfall.…

Honolulu forum threads describe January as genuinely pleasant, with a typical high around 81F and posters citing a comfortable range of roughly 78-85F. Rain does happen - one poster's data put the monthly average around 2.9 to 3.5 inches - but it wasn't described as the rainiest month, and posters were consistent that showers tend to pass quickly rather than settling in for the day. A real geographic detail flagged repeatedly: Waikiki and Honolulu sit on the drier southern shore of Oahu, while the North Shore sees noticeably more rain this time of year. Posters described the typical pattern as stretches of two to three weeks of sun occasionally interrupted by a passing winter storm bringing a few rainier days.

February is dry-ish season and the trade winds are steady, which is what makes 27°C pleasant rather than heavy. It's also peak north-shore swell — great to watch, not to swim. Whale season, which no climate score will tell you.

Regulars call this one of the island's best all-round weather months, sunny and warm without the summer's added heat, and are specific that a steady trade wind is a genuinely good sign here rather than something to worry about - it's what keeps the heat and humidity in check. Our row backs the pleasant read, 27.9C reading as a real 30C, over 21.6C nights, with 51.6mm of rain across 6.9 days. Regulars note the odd rough-wave day can still turn up on the North Shore even in an otherwise settled month, and a light sweater is worth packing for restaurants running strong air conditioning or a cooler evening. The sea sits at a warm 25.1C. The record: humidity 73 percent, 11.3 hours of sun, a 21.3 kph wind and AQI 38.

Regulars name a specific, checkable reason this month stays quieter than peak season: kids are still in school and there's no spring break landing in May, so crowds thin out well before the Memorial Day rush arrives. Our row backs the warm, dry-season read, 28.7C reading as a hot 31C, over 22.3C nights, with rain modest at 44.9mm across 5.8 days. Regulars are consistent this counts as the start of the dry season proper, sunny most days with a steady breeze off the water, and specifically call out flowers coming into bloom island-wide this time of year as a seasonal bonus. The sea sits at a warm, swimmable 24.8C. The record: humidity 73 percent, 12 hours of sun, a 20.9 kph wind and AQI 38.

June in Honolulu is sun, mid-80s Fahrenheit and trade winds, and the forum's point is that the wind is doing more work than the temperature. The trades blow their strongest in the summer months, and what they carry away is the vog - the volcanic haze that drifts up from the Big Island and only becomes a problem on Oahu when the north-easterlies are too weak to push it offshore. June is usually the good case for that, with the honest caveat that nobody can predict a volcano. The same wind is why the humidity feels lower than the figure: our row gives 72 percent with a 22 kph breeze. The record: 29.7C days that feel like 32C, 23.2C nights, 4.8 precipitation days carrying 32.2mm and a 25.7C sea.

July is the driest month here and regulars say that is also why it is the least humid - less rain, less moisture. Our row gives 23.7mm across 7 days at 73 percent. The month's real mechanism is the trade wind, which is steadiest now, at or above its yearly average about nineteen days in twenty. It does three jobs at once: it makes 30.4C bearable, it keeps the vog away - twenty miles an hour pushes it well offshore - and on the rare July day it fails, regulars remember the discomfort. Our wind reads 23.7 kph. Crowds are the cost, with July and August the peak and Waikiki much busier than the rest of the island. The record: 24.2C nights, 12.3 hours of sun and a 26.4C sea.

Honolulu forum regulars call August genuinely hot and dry rather than a mild tropical warmth: “high temperatures average in the low 90s°F,” with August the least likely month to get rain, the tradewinds doing most of the work keeping it bearable. The exception regulars flag: “trade showers on the windward side or closer to the mountains” can still catch a visitor even on an otherwise dry-forecast day. Ocean water runs “high 70's, maybe even 80's” — genuinely warm swimming. The honest trade-off regulars name: great for a pure beach trip, but if you want to do any sightseeing or hiking, winter is better, since August heat makes exertion genuinely uncomfortable. Our record: 28.4°C days, 6 rain days and a 26.7°C sea — hot and dry with a warm, swimmable sea, matching the “beach month, not a hiking month” read.