St. Augustine in April: Weather, Sea Temperature, Crowds and the Two Forts

ST. AUGUSTINE · APRIL · EASTERN TIME

April hands St. Augustine its friendliest set of numbers. Afternoons average 79.8°F, nights drop to 56.4°F, and the month records fewer wet days than either March or May. The Atlantic has stopped being cold without yet turning into bathwater, and the whole month sits ahead of hurricane season, which opens June 1.

What April withholds is warm water. At 71.8°F the sea is a decision rather than a default, and swimmers who want to spend the afternoon in it are four weeks early. Everything that is not dated by the month, from where to sleep to how to drive the coast, belongs to our St. Augustine guide.

On this page

• St. Augustine weather in AprilHighs of 79.8°F, lows of 56.4°F, 4.4 rain days
• Can you swim in April?The sea at 71.8°F, and the flag system
• Hotel booking and taxes in AprilA 5% county rental tax on top of 6% state sales tax
• Things to do in AprilCastillo de San Marcos, Fort Matanzas, the 1874 lighthouse
• A two-day plan for AprilTwo days from the 6:56 a.m. sunrise
• April, March or May?How the three months compare
• Is April a good time to visit?Our verdict on the month

April closes Florida’s dry season, and the figures here are climate normals rather than a forecast: they tell you what to pack, not what your Tuesday will do. The drive in from JAX or MCO and the statewide calendar are handled in when to visit Florida.

St. Augustine weather in April: average highs, lows and rain days

The normals below are station normals, not a grid reanalysis: NOAA NCEI’s 1991-2020 file for station USW00013889, the official thermometer at Jacksonville International Airport up the coast. It gives April an average high of 79.8°F, an average low of 56.4°F and 2.93 inches of precipitation. Downtown St. Augustine sits closer to the ocean than that runway does, and we found no downtown series to compare it with, so read the low as a regional figure.

Rain arrives in few visits. In an average April, 4.4 days record 0.10 inch or more, roughly one day in seven, and 0.9 day reaches a full inch. For a week’s stay that is one genuinely wet afternoon plus a shower that dries off the coquina before lunch is over. The Castillo’s $15 ticket stays valid 7 consecutive days, so a soaked morning costs you the order of your plans and nothing else.

The gap between 79.8°F and 56.4°F is 23.4°F, and it is the widest thing about April here. Pack for both ends: a light jacket for a 6:56 a.m. start along the seawall and for dinner outside, short sleeves for a 3:00 p.m. walk between the forts. Sea breeze shaves a few degrees off the afternoon near the water on some days, and nothing we read quantifies that, so we give no figure for it.

April 15 brings 12 hours 58 minutes of daylight, sunrise at 6:56 a.m. and sunset at 7:53 p.m. Eastern time. St. Augustine sits east of the Apalachicola River, so it keeps the same clock as Orlando and Miami. Because the Castillo pushes everyone out at 5:15 p.m., you still have more than two and a half hours of light for the bayfront, the beach and dinner.

Can you swim in St. Augustine in April? Sea temperature and beach flags

Off St. Augustine the sea surface averages 71.8°F in April, from Open-Meteo Marine’s 2015-2024 record. Read the number for what it is: a mean of daily maxima, so it describes the warmest reading of a typical day and sits a shade above a 24-hour average. A 7:00 a.m. swim is cooler than 71.8°F; a 4:00 p.m. one is about right.

At that temperature the water is swimmable rather than warm. Visitors from the Northeast and the Midwest walk in without discussion. Floridians tend to hold out for May’s 77.6°F. Kids will stay in until their lips go blue, and a rash guard buys an adult an extra half hour. Florida’s warning flags do the rest of the talking: green low hazard, yellow medium, red high, double red for closed water, purple for dangerous marine life flown beside another flag.

Wind and swell we cannot give you: we found no verified April wind or wave normals for this stretch of coast, and we will not estimate them. The calendar is clearer. April falls outside the Atlantic hurricane season, June 1 to November 30 by NOAA’s definition, peaking September 10 with most activity between mid-August and mid-October. No law compels a beach to fly any flag at all, so find the lifeguard stand before you trust an empty pole, and our safety guide covers rip currents.

How busy is St. Augustine in April? Crowds, hotel booking and the county bed tax

April is the last month of the statewide dry season that runs November through April, the stretch that fills Florida for obvious reasons: warm, dry, no tropical systems to track. Demand follows that calendar and school breaks stack inside it. We found no occupancy series and no monthly room-rate series for St. Johns County, so we crown no month cheap and none expensive. We also verified no hotel, no nightly rate and no restaurant, so we name none.

Book the bed before the flight. JAX, the nearest large airport, boarded 3,749,791 passengers in 2024 as a medium hub, while Orlando MCO boarded 27,859,783. The practical consequence is fewer nonstops into Jacksonville and a wider, sometimes cheaper choice into MCO with a longer drive attached. For a three-night April weekend we would lock lodging several weeks out and stay flexible on the flight. Getting around covers the car you will want for Fort Matanzas.

St. Johns County levies a 5.0% transient rental tax on short stays, filed and paid alongside Florida’s 6% state sales tax. That is 11% on top of the room rate, before any resort fee or parking charge a property adds on its own. Both rates apply in every month, so April changes the base the percentage is charged on and not the percentage itself. The wider budget sits in what a Florida trip costs.

The one upgrade that changes April specifically is walking distance. Sunset on April 15 falls at 7:53 p.m. and the Castillo shuts its gate at 5:15 p.m., so the best hours of the month are spent on foot after the monuments empty. A room you can walk back to means the car stays parked from arrival until the drive south. Pay more anywhere else and you buy comfort, not a different month.

Things to do in St. Augustine in April: Castillo de San Marcos, Fort Matanzas and the lighthouse

April allows what July forbids: a whole day spent outdoors on stone and boardwalk. A 79.8°F average high keeps the Castillo’s gun deck walkable at noon, when a summer afternoon would send you looking for air conditioning by one o’clock. The 56.4°F nights keep an evening in the old streets comfortable, and the month arrives before the wet season turns every afternoon into a thunderstorm watch.

Two of Florida’s eleven National Park Service units are here, and neither carries the National Park title: Castillo de San Marcos, which the Park Service calls the oldest masonry fortification in the continental United States, and Fort Matanzas, a coquina watchtower completed in 1742 to guard the southern approach to the Spanish settlement. The Castillo charges $15 for visitors 16 and up, valid 7 consecutive days, with under-16s free when an adult comes along. First admission 9:00 a.m., last 5:00 p.m., gates cleared at 5:15.

The stone does not change with the month; the air does. Coquina was the only local stone the Spanish had, and it holds the night: the gun deck at 9:00 a.m. sits near April’s 56.4°F low, the same deck at 3:00 p.m. near its 79.8°F high. April also catches the lighthouse on its long schedule. From March 1 to September 30 it runs 9:00 a.m. to 6:30 p.m., last ticket 6:00 p.m. The 1874 tower climb comes with general admission, children under 44 inches cannot go up, and we could not verify the admission price.

Free in April, as in every month: every area of Fort Matanzas National Monument, the ferry to the fort included. The catch is procedural. Boarding passes cost nothing but are issued at the Fort Matanzas Visitor Center, not the city visitor center downtown, and every family member needs one regardless of age. The ferry service operates October 1 to September 30. Call before you drive to confirm departure times. Below the mean high-water line the beach is public, while dry sand above it can be private under Florida Statutes 163.035.

St. Augustine in April: a two-day itinerary

Day one stays downtown and on foot. Sunrise is 6:56 a.m., which makes the bayfront an easy first hour. Be at the Castillo for first admission at 9:00 a.m., pay the $15 once and keep the ticket, since it covers 7 consecutive days. Give the walls two hours while the morning is still closer to the 56.4°F low than to the 79.8°F high. Take the middle of the day slowly, then walk the old streets from 5:15 p.m., with light holding until 7:53 p.m.

Day two runs south. Stop at the Fort Matanzas Visitor Center first for the free boarding passes, one per person, then cross to the 1742 watchtower. Head back north for the lighthouse, where the last ticket at 6:00 p.m. leaves the climb to the afternoon. If your day turns into the one inch-plus soaking the month averages 0.9 times, invert the order: the Castillo ticket is still good tomorrow, so trade the tower for the fort and save the crossing for the clear day.

St. Augustine in April vs March and May

Temperature climbs in one direction across the three months and rain does not. March averages a 74.3°F high and a 50.6°F low, April 79.8 and 56.4, May 85.9 and 63.9. Rain is where April wins outright: 2.93 inches across 4.4 days at 0.10 inch or more, against March’s 3.29 inches across 5.6 days and May’s 3.42 inches across 4.6. The sea moves steadily through the spring, 67.6°F in March, 71.8°F in April, 77.6°F in May.

Shifting four weeks back to March buys cooler afternoons at 74.3°F and costs 4.2°F of water plus 1.2 more wet days. Our March page takes that month apart. Shifting forward to May buys 5.8°F of sea, enough to turn swimming from a decision into the default, and costs the mild night: 63.9°F instead of 56.4, with 85.9°F afternoons waiting on the walls.

Is April a good time to visit St. Augustine?

Yes, for anyone whose trip is built on walking, forts and long evenings. April delivers near-80°F afternoons, the fewest wet days of the spring at 4.4, almost 13 hours of daylight and no tropical system to watch before June 1. No, if the ocean is the point. A 71.8°F mean of daily maxima means brisk entries and short swims, and the hotel pool will end up doing more work than the Atlantic.

Swimmers should move to May: 77.6°F water and 85.9°F highs, paid for with warmer nights and 3.42 inches of rain. Going the other way makes sense only for a specific reason, and that reason is comfort on a long fort day. March’s 74.3°F high is the kindest of the three for six hours on coquina, while its 5.6 wet days and 67.6°F sea are the bill.

April alone puts all three together: the driest month of the spring at 2.93 inches, water already past 70°F, and a hurricane season that does not start for another six weeks.

The last word

Decide one thing: whether this is a swimming trip. If it is, take May and its 77.6°F water. If it is not, April is the better version of the same city, and the smart move is buying the $15 Castillo ticket on the first morning so its 7 valid days absorb the one wet afternoon the month averages. Two things to know before you go: the Park Service dates the founding of St. Augustine to 1565, the familiar oldest-city superlative appears on none of the NPS pages we read, and the river you cross to Fort Matanzas carries the Spanish word for slaughters.

Sources & data for this guide

• April highs, lows, precipitation and rain-day counts · NOAA NCEI monthly normals 1991-2020, station USW00013889 (Jacksonville International Airport) · checked Sep 23, 2026
• March and May normals used in the comparison · same NOAA NCEI file and period · checked Sep 23, 2026
• Sea surface 71.8°F as a mean of daily maxima · Open-Meteo Marine API, 2015-2024 average · checked Sep 23, 2026
• Daylight, sunrise and sunset on April 15, converted to Eastern time · sunrise-sunset.org · checked Sep 23, 2026
• Hurricane season dates and September 10 peak · NOAA National Hurricane Center · checked Sep 23, 2026
• Castillo de San Marcos fees, hours and coquina construction · National Park Service (Fees, Hours, Stories pages) · checked Sep 7 and 8, 2026
• Fort Matanzas free entry, boarding passes, ferry season, the 1742 tower, the 1565 founding date and the meaning of Matanzas · National Park Service · checked Sep 23, 2026
• Lodging tax: 5.0% St. Johns County transient rental tax with 6% state sales tax · Florida Department of Revenue, form DR-15TDT · checked Sep 23, 2026
• Lighthouse hours and the 44-inch rule for the tower · St. Augustine Lighthouse & Maritime Museum · checked Sep 23, 2026
• Airport boardings, JAX and MCO, CY2024 · Federal Aviation Administration · checked Sep 23, 2026
• Beach warning flags and beach access above the mean high-water line · Florida Statutes 380.276 and 163.035, Volusia County Beach Safety · checked Sep 23, 2026
• We could not verify the lighthouse admission price, the ferry’s daily departure times, any dated April event, or any hotel or restaurant, so we give none. Hours and fees change · check the operators when you book.

To plan your stay

• Things to Do in St. Augustine: Castillo Tickets, Fort Matanzas Ferry and Lighthouse Hours
• Where to Stay in St. Augustine: Historic District, the Beach and the 5% Lodging Tax
• Airport to St. Augustine: JAX, MCO, Rental Cars and Eastern Time
• St. Augustine Know Before You Go: Castillo Fees, the Fort Matanzas Ferry Pass and Beach Rules

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• Blue Spring, Florida: Water Temperature, Swimming and Parking Limits