Honolulu in April: Weather, Sea Temperature and How It Compares to March and May

HONOLULU · APRIL · 21.3° N

April is the month Honolulu dries out. The gauge at the airport collects 2.36 inches in an average March and 0.77 inches in an average April, and that difference is the whole character of the trip: an afternoon you sketch at breakfast tends to survive the day. Highs average 83.1°F, the water off the south shore runs 76.7°F, and on the 15th the sun is still up at 6:52 pm.

What April asks in return is a calendar check. Mainland spring breaks and the Easter school holiday land somewhere in these four weeks and move from year to year, so the week you pick decides how your flights and rooms price long before the weather does. Five to seven nights is the shape that fits a first Oahu trip without a second island bolted on.

On this page

• Honolulu weather in AprilHighs of 83.1°F and 1.9 wet days
• Sea temperature for swimming76.7°F off the south shore
• Crowds, booking and lodging taxSpring-break weeks and the tax figure we don’t carry
• Things to do in AprilWaikiki, Ala Moana and Diamond Head
• A two-day Honolulu itineraryTwo days between 6:10 am and 6:52 pm
• April vs March and MayHow the three months compare, in one table
• Is April a good time to visit?Who should book it and who should shift

Every figure here carries a named source, and two of them deserve naming up front. The air normals are station data from a real thermometer at the airport, not a model grid cell. The sea temperature comes from a marine model and is an average of daily maxima. Where a number you read elsewhere disagrees with one below, the method is usually the reason.

Honolulu weather in April: average highs, lows and rain days

The air numbers come from NOAA’s National Centers for Environmental Information, the 1991-2020 monthly normals for station USW00022521, which is the gauge at Honolulu International Airport on the leeward south shore. April averages a high of 83.1°F, a low of 70.1°F and 0.77 inches of precipitation. That instrument sits a short drive from Waikiki and reads the dry side of Oahu: the windward coast and the mountains behind it take several times as much rain, and the normals below do not see a drop of it.

Measurable rain is genuinely scarce in that record. An average April logs 1.9 days with 0.10 inch or more, roughly one day in sixteen, which is closer to a wet hour than to a wet day for most visitors. Plan the indoor part of your itinerary as something you can slide rather than something you cancel, and keep the beach where it is.

Thirteen degrees separate the average low from the average high, 70.1°F to 83.1°F, and the low arrives near dawn rather than at dinner. The packing list stays short because of it: what you swim in, one light long-sleeve layer for the evening, a thin shell for the day and a half of rain. Nothing heavier than a sweatshirt is going to come out of the suitcase.

On April 15 the city gets 12 hours 42 minutes of daylight, with sunrise at 6:10 am and sunset at 6:52 pm local time, per sunrise-sunset.org. Those two clock times do more scheduling work than the temperature does. An early trail is finished before the heat, and a table outside at 6:30 still comes with light on it.

Can you swim in Honolulu in April? Sea temperature and what it feels like

Sea surface off Honolulu averages 76.7°F in April in the Open-Meteo Marine API record for 2015-2024. Read that with its caveat attached: it is the mean of daily maxima, the afternoon end of each day, so it runs a shade warmer than a 24-hour mean would. A table built on 24-hour averages will show a slightly lower figure for the same water, and neither number is wrong.

Against an 83.1°F afternoon, 76.7°F water reads cool for about ten seconds and then stops registering. Most adults swim in it without a second thought and stay in for an hour. Floating still over a reef with a snorkel is different from moving, so a rash guard is worth the space in the bag, and children tend to notice the temperature well before the grown-ups on the sand do.

No wave-height or wind series was read into our fact base, so nothing here will tell you which shore is flat in April. Check the day’s forecast and the lifeguard flags before choosing a beach. The rain caveat matters for the same decision: a morning that reads dry at the airport gauge can be showery at a windward trailhead half an hour away.

How busy is Honolulu in April? Crowds, prices and the demand peak

Our fact base for this month covers climate and sea temperature, not occupancy or room rates, so nothing here ranks April against the other eleven months on price. The calendar is the part we can name. Mainland spring breaks and the Easter school holiday fall somewhere inside these four weeks, both move from year to year, and the week you choose decides what you pay far more than the month does.

That movable holiday is the entire booking problem. Flights and rooms for the Easter-adjacent days behave differently from the weeks on either side of them, and how many weeks ahead to commit is not something our data pins down. Book a refundable rate, look up your own school district’s dates, then recheck once rather than lock in early on a guess.

No lodging-tax rate was read into our fact base, so no percentage appears in it. We are not going to quote a figure we have not checked, and a Hawaii quote picks up tax and, at many properties, a daily fee on top of the headline rate. When two hotels look close, compare the totals at the bottom of the checkout page, not the nightly numbers at the top.

If one budget line deserves the upgrade in April, it is walking distance to the water. With sunset at 6:52 pm and the ocean at 76.7°F, a bed you can reach the sand from turns the last hour of daylight into something you use every single evening instead of a drive and a parking search. A rental car you only need on two of five days is the cheaper thing to cut.

Things to do in Honolulu in April: Waikiki, Ala Moana and Diamond Head

April’s 0.77 inches against March’s 2.36 is what opens the walking. Red-dirt ridge trails that stay greasy through the wet months have usually drained by now, at least on the side of the island the airport gauge speaks for, and a hike planned at breakfast tends to still be on at noon. That reliability is the practical gift of the month.

Waikiki Beach is the default swim, and the water it opens onto is the 76.7°F above. Ala Moana Beach Park, one bay to the west, is the flatter and calmer of the two. Diamond Head State Monument is the walk nearly everyone does, exposed and unshaded the whole climb, which makes it a job for the hour after the 6:10 am sunrise rather than for 11 am under an 83°F sky. Entry fees, parking charges and the reservation systems at several Oahu sites were not read, so check the operator the week before you drive out.

The ocean barely notices the calendar: 76.0°F in March, 76.7°F in April, 77.0°F in May, a single degree across a quarter of the year. The air moves further over the same span, 81.2°F to 84.8°F, and the rain moves most of all, from 2.36 inches to 0.77. Same reef, same trail, a drier and brighter sky over both of them.

Nothing in our fact base prices a ticket for April, so treat the paid list as something to verify rather than something we have quoted. What costs nothing is the part this month does best anyway: 12 hours 42 minutes of daylight to spend, a swim in 76.7°F water, and the shoreline at 6:52 pm.

Honolulu in April: a two-day itinerary

Day one runs on the clock rather than the map. Be moving by the 6:10 am sunrise, when the air is near its 70.1°F end, and take Diamond Head or the Ala Moana shoreline while it lasts. Breakfast after, in the water by nine, then shade or an indoor hour from noon to two while the 83.1°F peak goes by. Back in the ocean around four, and dinner outside before 6:52 pm so you eat in daylight.

Day two goes across the island or into town: the Pearl Harbor memorials in the morning, with the ticketing system checked the night before, then the windward coast for the afternoon swim. If the showers arrive, you have landed in the 1.9-day minority for the month, so pull the indoor hour forward and use the Bishop Museum or the Waikiki Aquarium. Remember that the 0.77-inch figure belongs to the airport, and the windward side you just drove to keeps its own weather.

Honolulu in April vs March and May

March runs 81.2°F by day with 2.36 inches of rain over 3.1 wet days. April drops the rain to 0.77 inches and 1.9 wet days while adding nearly two degrees to the afternoon. May goes a little further again, 84.8°F and 1.6 wet days at 0.82 inches. The air normals for all three come from the same NOAA station and the same 1991-2020 period, while the three sea figures come from the Open-Meteo Marine API on 2015-2024, a different source over a different span.

Shift four weeks earlier and March costs you three times the rain, two degrees off the afternoon and 0.7°F off the water. Shift four weeks later and May adds 1.7°F to the high and 0.3°F to the sea while holding rain within 0.05 inch of April. Between April and May the weather argument is thin and the school calendar decides it. Between March and April, the rain decides it on its own.

Is April a good time to visit Honolulu?

Yes, for anyone building the trip around water, sand and trails, which covers most first visits to Oahu. The month delivers swimming weather, dry ground and long evenings without asking anything difficult of the packing list. It is a weaker pick for a traveler with a fixed budget, no date flexibility and a week that happens to collide with the Easter holiday.

If your dates are movable and April looks crowded on the school calendar, May is the smaller of the two shifts. It keeps the dry pattern, 0.82 inches over 1.6 wet days, adds 1.7°F to the afternoon and 0.3°F to the sea, and moves you clear of the spring-break window. March is the shift to avoid on weather grounds alone, given the 2.36 inches.

What April alone gives you is the collapse of the rain to 0.77 inches at a point when the water has already climbed to 76.7°F, a pairing March cannot offer at all and May can only repeat under a hotter sun.

The last word

Book the bed you can walk to the water from, keep the rate refundable until you have checked the Easter dates against your own calendar, and schedule the climb for the 6:10 am end of the day. One figure from the NOAA record has not been served yet, and it settles most of the weather worry: an average April produces 0.1 days with an inch of rain or more, which works out to roughly one April in ten recording a one-inch day at the airport. A thin shell handles that, and the itinerary stays as written.

Sources & data for this guide

• April air normals (83.1°F / 70.1°F, 0.77 in) and rain-day counts (1.9 days at 0.10 in, 0.1 day at 1 in) · NOAA NCEI monthly normals 1991-2020, station USW00022521, Honolulu International Airport · checked Sep 15, 2026
• March and May air normals used in the comparison table · NOAA NCEI monthly normals 1991-2020, same station · checked Sep 15, 2026
• Sea surface 76.7°F in April, 76.0°F in March, 77.0°F in May, all as means of daily maxima · Open-Meteo Marine API, 2015-2024 average · checked Sep 15, 2026
• Daylight of 12h 42m and the 6:10 am / 6:52 pm clock times on April 15 · sunrise-sunset.org, converted from UTC to Hawaii local time · checked Sep 15, 2026
• Scope caveat: the station is on the leeward south shore and does not measure windward or mountain rainfall · NOAA NCEI station metadata · checked Sep 15, 2026
• Not read for this page, and therefore not quoted: lodging-tax rates, hotel occupancy or room-rate series, site entry fees, wind and wave data. The crowd and budget advice above is editorial.
• Place names, itineraries and hours change · check the operator before you travel.