Hawaii, USA · The Aloha State
weather across hawaii — the state where the trade winds decide everything.
Hawaii is the most isolated major populated archipelago in the world, sitting 2,400 miles from the nearest continent in the middle of the North Pacific. The state contains eight main islands with five active volcanoes, peaks over 13,000 feet, and the most dramatic windward-versus-leeward climate split of any US state. Trade winds blow from the northeast across the volcanic terrain, producing the wettest places on Earth on the windward sides and rain shadow deserts on the leeward sides — sometimes within five miles of each other.
What is the weather like in Hawaii?
Hawaii has a tropical maritime climate with persistent trade winds blowing from the northeast year-round. The windward (eastern) sides of the islands receive heavy orographic rainfall — Hilo on the Big Island averages 126 inches/year. The leeward (western) sides sit in dramatic rain shadows — Honolulu averages just 17 inches/year. Hurricane season runs June through November but direct impacts are rare. The state has no real winter and minimal seasonal temperature variation.
The seasons, honestly
seasons in hawaii.
Hawaii seasons collapse into two: warmer and slightly cooler. The state has no winter in any meaningful sense. Average July high in Honolulu is 88°F; average January high is 81°F — a seasonal range of just 7°F, the smallest of any US state. The trade winds blow from the northeast for roughly 80% of days each year, driving the daily weather patterns and producing the consistent temperatures that define the tropical maritime climate.
The wet season (October–April) brings most of the state’s rainfall through stronger trade wind events and the occasional Kona storm (the rare reversal of the trade wind pattern that brings southwest winds and heavy rain to leeward areas). The dry season (May–September) features more consistent trade winds and lighter rainfall, though the windward sides receive precipitation year-round regardless of season.
Hurricane season officially runs June 1 through November 30, with the climatological peak in August and September. Direct hurricane impacts on the Hawaiian Islands are historically rare — only Hurricane Iniki in 1992 (Category 4 direct hit on Kauai) and Hurricane Lane in 2018 (heavy rainfall on the Big Island) have produced major impacts in modern memory. The cold North Pacific waters typically weaken tropical systems before they reach the islands.
Defining weather events
what the sky does in hawaii.
Hawaii weather is defined by two large-scale mechanisms working together. The persistent northeast trade winds blow across the Pacific for thousands of miles before reaching the islands, producing the tropical maritime conditions and the consistent year-round temperatures. The trades drive the daily weather pattern — morning sun, afternoon shower bands on the windward sides, evening clearing.
The volcanic terrain produces the second mechanism: the orographic uplift effect that creates the most dramatic windward-versus-leeward climate split of any US state. When trade winds hit the slopes of Mauna Loa, Mauna Kea, the Koolau Range, the Waianae Range, and Haleakala, they are forced upward, cool, and condense into rainfall. The windward sides receive 100–300+ inches of annual rainfall in some locations (Mt. Waialeale on Kauai is one of the wettest places on Earth at over 460 inches/year). The leeward sides receive 10–20 inches of annual rainfall — desert conditions just a few miles from rainforest.
Kilauea on the Big Island has been one of the most active volcanoes in the world for the past several decades, producing vog (volcanic smog) that affects air quality across the islands during eruption events. The 2018 eruption produced devastating lava flows that destroyed over 700 structures.
Northeast trade winds blow at 10–20 mph for roughly 80% of days year-round, driving the daily weather pattern and producing the consistent tropical conditions. The trades occasionally weaken or reverse during Kona storm events.
Trade winds hitting the volcanic slopes produce dramatic orographic uplift and rainfall. Hilo averages 126 inches/year; Mt. Waialeale on Kauai averages over 460 inches/year, one of the wettest places on Earth. Windward Oahu averages 60–100 inches.
Pacific hurricane season produces tropical systems that occasionally threaten Hawaii. Direct hits are rare — Hurricane Iniki (1992, Category 4) on Kauai and Hurricane Lane (2018, heavy rainfall) on the Big Island are the most significant recent events.
Active eruptions of Kilauea on the Big Island produce vog — volcanic smog made of sulfur dioxide and other gases. When trade winds blow steadily from the northeast, vog moves toward the southwest and away from populated areas. Kona winds (rare reversal) bring vog onto Hilo and the Big Island’s northeast coast.
Hawaii sits in the middle of the Pacific Rim of Fire and is vulnerable to tsunamis from earthquakes around the Pacific basin. The 1960 Chilean tsunami killed 61 people in Hilo. The 2011 Tohoku tsunami produced significant impacts on the Big Island. Tsunami evacuation zones are marked across all the islands.
Best cities, by season
where to be in hawaii.
Hawaii’s best season depends entirely on which side of the islands you visit and what you came for. The leeward (western) sides are sunny and dry year-round; the windward (eastern) sides are wet and lush year-round. Honolulu is the urban anchor; Hilo is the rainforest gateway.
What other weather apps get wrong
why hawaii needs a different forecast.
Generic weather apps treat Hawaii as one tropical paradise. They show "sunny and 82°F" for both Honolulu and Hilo as if both islands have the same forecast when Honolulu sits in the leeward rain shadow of the Koolau Range and Hilo sits in the windward orographic uplift zone of Mauna Loa. The two cities are 200 miles apart and receive 17 inches and 126 inches of annual rainfall respectively — the largest single-state rainfall difference in the United States.
They miss that the trade winds drive the entire daily weather pattern, that the volcanic terrain produces dramatic microclimate variation, that the vog from active Kilauea eruptions affects air quality across the islands, and that the tsunami risk is real and constant. AccuWeather treats the leeward and windward sides of every island as the same forecast despite the trade winds making them entirely different climates.
The Vesper Brief reads Hawaii as the trade-wind-dominated tropical archipelago it actually is and writes the windward-versus-leeward climate split as the meteorological event it actually is rather than as "sunny with afternoon showers."
Unlike Apple Weather, Vesper writes for the part of Hawaii you actually stand in.
Frequently asked
about hawaii weather.
Frequently Asked Questions
Why is Hilo so much wetter than Honolulu?
Hilo sits on the windward (eastern) side of the Big Island, directly in the path of trade winds blowing across thousands of miles of open Pacific Ocean. When the trades hit the slopes of Mauna Loa (13,679 ft) and Mauna Kea (13,803 ft), the air is forced upward, cools, and condenses into rainfall. Hilo averages 126 inches of annual rainfall. Honolulu sits on the leeward (western) side of Oahu in the rain shadow of the Koolau Range, receiving just 17 inches/year — the largest single-state rainfall difference in the United States.
When is hurricane season in Hawaii?
Pacific hurricane season runs June 1 through November 30, with the climatological peak in August and September. Direct hurricane impacts on Hawaii are historically rare — the cold North Pacific waters typically weaken tropical systems before they reach the islands. Hurricane Iniki (1992, Category 4) was the most destructive direct hit in modern memory, causing significant damage on Kauai. Hurricane Lane (2018) produced heavy rainfall and flooding on the Big Island despite passing offshore.
What are the trade winds and how do they affect Hawaii’s climate?
Trade winds are persistent northeasterly winds that blow across the tropical Pacific for thousands of miles before reaching Hawaii. They drive the islands’ daily weather pattern, the windward-versus-leeward rainfall split, and the consistent year-round temperatures. The trades blow at 10–20 mph on roughly 80% of days, with stronger trade events producing rougher seas and the rare Kona storm reversing the pattern during winter.
Does it ever get cold in Hawaii?
Not in any meaningful sense at sea level. Honolulu’s average January low is 65°F, and the city has never recorded a freezing temperature. The high elevations of Mauna Loa and Mauna Kea on the Big Island and Haleakala on Maui can experience freezing temperatures and even occasional snow at the summit (above 13,000 feet on Mauna Kea), but the lowland populated areas never see winter as the rest of the US would recognize it.
How active are Hawaii’s volcanoes?
The Big Island has five volcanoes: Mauna Loa, Mauna Kea, Hualalai, Kohala, and Kilauea. Kilauea is one of the most active volcanoes in the world and has been erupting nearly continuously since 1983 (with periodic pauses). The 2018 eruption produced devastating lava flows that destroyed over 700 structures in the Lower Puna District. Mauna Loa erupted briefly in 2022 — the first eruption since 1984. The volcanic activity affects local air quality through vog and produces the dramatic landscape that defines the Big Island.
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