SILVER GLEN SPRINGS · FLORIDA · SEPTEMBER
The vent was moving 87 cubic feet of water per second when the USGS gauge was read on September 11, 2026, and a spring run does that in September much as it does in February. Air is what changes. NOAA’s September normals for the nearest official station run 88.1°F by day, 69.4°F at night, and 5.05 inches of rain across the month, and that last figure is the part a September trip has to plan around.
Against August, September takes 2.4 degrees off the average high and cuts the wet days from 10.4 to 6.9. Against October, it holds on to 6 degrees of afternoon warmth and 8.8 degrees of nighttime warmth, and pays for both with 2.37 extra inches of rain. It also sits on the statistical peak of the Atlantic hurricane season, around September 10 (our Florida orientation carries the NOAA source for that date).
THE MONTH AT A GLANCE · SEPTEMBER
September keeps August’s swimming air, cuts its wet days by a third, and asks you to book refundable because the month sits on the peak of hurricane season.
NOAA 1991-2020 NORMALS · HIGH 88.1°F · 6.9 WET DAYS · 12H 22M OF DAYLIGHT ON THE 15TH
Go for: warm-air swimming with 6.9 wet days instead of August’s 10.4, long light until 7:32 p.m. on the 15th, and a run that carries 87 cubic feet a second whatever the calendar says.
Think twice before: booking non-refundable, since September 10 is the statistical peak of the Atlantic hurricane season and your dates may need to move.
Air: NOAA NCEI 1991-2020, Gainesville Rgnl AP · Flow: USGS gauge 02236160 · full sources at the end
On this page
- Average highs, lows and rain days88.1°F, 69.4°F and 6.9 wet days
- What to wear at dawn and at 4 p.m.The 18.7-degree daily swing
- Fees, hours and how busy the month runsWhat we verified, and what we could not
- Things to do in SeptemberThe spring run and its 87 cubic feet a second
- A two-day plan built on the daylightSunrise 7:10 a.m., sunset 7:32 p.m.
- September against August and OctoberThree months of NOAA normals side by side
- Is September the right month?Who should go, who should wait
- The month before at Silver Glen SpringsAugust: 90.5°F highs and 10.4 wet days
Every figure here for air and rain comes from one thermometer: NOAA’s 1991-2020 monthly normals for Gainesville Regional Airport, station USW00012816, about 78 km from the spring, roughly 48 miles. That is a station record rather than a gridded reanalysis, and it measures air over a runway, not water in a vent. Read the normals below as the weather you will drive through and sit in, not as the temperature you will swim in.
Silver Glen Springs weather in September: average highs, lows and rain days
| Measure | September | Source |
|---|---|---|
| Average high | 88.1°F | NOAA NCEI 1991-2020 |
| Average low | 69.4°F | NOAA NCEI 1991-2020 |
| Precipitation | 5.05 in | NOAA NCEI 1991-2020 |
| Days with 0.10 in or more | 6.9 | NOAA NCEI 1991-2020 |
| Days with 1 in or more | 1.4 | NOAA NCEI 1991-2020 |
| Daylight, Sep 15 | 12h 22m · 7:10 a.m. to 7:32 p.m. EDT | sunrise-sunset.org |
| Spring flow | 87 cu ft/s | USGS gauge 02236160 · Sep 11, 2026 |
Three numbers carry the month at Gainesville Regional Airport: 88.1°F for the average daily high, 69.4°F for the average low, 5.05 inches for the total rain. They are thirty-year averages from a real instrument, averaged over 1991 to 2020, so no single September looks exactly like them. A run of five dry, 92-degree days and one day that dumps two inches both live inside that same 5.05.
On the rain side, 6.9 days in an average September record at least 0.10 inch, which works out to measurable rain roughly one day in four. Only 1.4 of those days reach a full inch, so a genuine soaking lands once or twice in a month, and the other 23 days stay dry or close enough to it. Florida’s wet-season rain tends to arrive in the afternoon rather than the morning, so the hour you get in the water matters more than the forecast percentage.
Between the average high and the average low sit 18.7 degrees, and the low lands before breakfast. Anyone arriving for a 7 a.m. parking spot wants a light layer that can come straight back off by nine, plus a dry shirt for the drive home after a day of 88-degree humidity. A towel that actually dries, and a hat, do more work in September than any piece of gear you would buy for it.
On September 15 the sun rises at 7:10 a.m. and sets at 7:32 p.m. local time, 12 hours and 22 minutes of daylight. That is a generous day by Florida standards, but the forest edge along a spring run steals the last half hour of usable light well before the official sunset, so treat 6:45 p.m. as the practical end of the swimming day.
How warm is Silver Glen Springs in September?
The air peaks at 88.1°F on an average day and bottoms at 69.4°F, an 18.7-degree swing across roughly twelve daylight hours. The water underneath does not follow that curve at all, and that constancy is the reason the place exists as a destination. We found no measured water temperature at the vent, only the discharge figure of 87 cubic feet per second read on September 11, 2026, so we quote no swim temperature here.
In practice you dress for two different days. A 69-degree dawn with humidity in it feels cool enough for a long sleeve over the swimsuit, and by ten that layer is in the bag. From one o’clock to about five, an 88-degree afternoon with full Florida sun rewards shade, a rash guard in the water, and more drinking water than you packed. Sandals that survive wet sand beat anything with laces.
Freezing nights are not a September concern at this latitude: the month’s average low of 69.4°F sits more than 37 degrees above 32°F, and the NOAA normals we read carry no freezing-day count for the month. Cold, when it shows up in this part of Florida, belongs to the pages for December and January rather than to this one.
How busy is Silver Glen Springs in September? Crowds, prices and the demand peak
We found no occupancy series and no monthly room-rate series, so we crown no month cheap and no month expensive. What the calendar does say is plain enough: Labor Day weekend opens September and closes the summer school break, and the three weeks that follow are the first stretch since May without a national school holiday feeding weekend traffic toward Florida’s springs.
On the booking side, we could not verify an opening hour, a closing time or a vehicle capacity for the spring, so we will not invent a lead time in weeks. Call the operator before you drive, and for lodging build the hurricane peak into the reservation rather than into your hopes. Our month-by-month view of Florida sets September in the wider state calendar.
We could not verify a lodging-tax rate either, so no percentage appears from us. The Florida costs that reliably surprise visitors are the ones our trip cost guide itemizes: resort fees, parking at the beach lots, and electronic-only tolls on the drive in.
There is one place where spending more genuinely changes a September trip, and it is the cancellation policy. A refundable rate during the statistical peak of hurricane season buys you the ability to shift a weekend by seven days, and in a month with 1.4 inch-plus rain days and a live tropical forecast, that flexibility is worth more than an upgraded room.
Things to do in Silver Glen Springs in September
September is the last month of the year that pairs August-grade swimming air with a rain column that has already started to fall. The high drops only 2.4 degrees from August’s 90.5°F, while the wet days go from 10.4 to 6.9, a third fewer. Four weeks later the air has given up six more degrees and the dawn has given up nearly nine, so the swim itself changes character.
The headline act is the run and the vent that feeds it. The USGS gauge numbered 02236160 measured 87 cubic feet per second leaving the vent on September 11, 2026, and that volume is exactly why the water reads so clear: it gets replaced faster than it can cloud. We could not verify an entrance fee, an opening hour or a manatee count, so we publish none of the three. The wider picture of the site lives on our Silver Glen Springs guide.
What September changes is not the water but the contrast around it. Climbing out at 4 p.m. into 88-degree air is comfortable enough that people stay in for hours; doing the same in October, with highs at 82.1°F and the shade cooling fast, turns the exit into the hard part. Shoulder-season swimmers feel that gap far more than the swimmers of the month itself.
One thing costs nothing and happens before you leave the house: the gauge reading is public. Station 02236160 publishes its discharge figure, and checking it the morning of the drive tells you more about the state of the run than any photograph taken last spring. Beyond that, we verified no free day and no fee at the entrance, so confirm both with the operator.
Silver Glen Springs in September: a two-day itinerary
Day one runs on the light. Leave early enough to be parked near 7:10 a.m. sunrise, swim from eight to eleven while the air is still climbing toward its 88.1°F average, then eat and shelter from one to four, the hottest and stormiest window of a Florida wet-season day. Back in the water at 4:30, out around 6:45, and the drive home starts in daylight that runs until 7:32 p.m.
Day two repeats the morning half and drops the late session, because two afternoons in that heat is one more than most people want. If the sky turns, remember the shape of the month: 6.9 days carry measurable rain and only 1.4 reach an inch, so a storm usually costs you the middle of the afternoon rather than the day. Keep a dry-weather alternative from our Florida things-to-do guide on the phone before you set off.
Silver Glen Springs in September vs August and October
| Measure | August | September | October |
|---|---|---|---|
| Average high | 90.5°F | 88.1°F | 82.1°F |
| Average low | 72.0°F | 69.4°F | 60.6°F |
| Precipitation | 6.40 in | 5.05 in | 2.68 in |
| Days with 0.10 in or more | 10.4 | 6.9 | 4.0 |
All twelve figures above come from the same NOAA 1991-2020 station record, so the comparison is like for like. September is 2.4 degrees cooler by day than August and 2.6 degrees cooler by night, differences a swimmer barely registers. The rain is where the three months separate: 6.40 inches over 10.4 wet days in August, 5.05 over 6.9 in September, 2.68 over 4.0 in October. The water leaving the vent does not vary between any of them.
Move four weeks later and you buy the driest of the three months and lose the warm exit, since October’s average low of 60.6°F is 8.8 degrees below September’s and the afternoon tops out six degrees lower. Move four weeks earlier and you take on 3.5 extra wet days for 2.4 degrees of extra warmth, a poor trade for anyone with fixed dates. Our August page makes the case for the month before.
Is September a good time to visit Silver Glen Springs?
Yes for swimmers, and yes for anyone who wants to spend six hours in and out of the water without shivering on the bank. Say no if your dates cannot move at all, because the month carries the statistical peak of the Atlantic hurricane season on September 10, or if your priority is a dry week outdoors: 5.05 inches is close to double what October delivers.
If the answer is no, October is the month to take, with 2.68 inches of rain across 4.0 wet days and highs still at 82.1°F. The price is a 60.6-degree average low, which makes early starts genuinely chilly and shortens the comfortable swimming window at both ends of the day.
What no other month offers is this particular pairing: air within 2.4 degrees of the August peak, wet days already down a third, and 12 hours 22 minutes of daylight on the 15th to spend them in.
The last word
Book the dates you can change, aim the car at a 7:10 a.m. sunrise, and let the afternoon storm window have the middle of the day. One fact worth carrying in: Florida law gives its strongest spring protections to a class it calls Outstanding Florida Springs, defined in Florida Statutes 373.802(5) as every historic first-magnitude spring identified by the Florida Geological Survey, plus six more written into the statute by name. That legal shield, and the 87 cubic feet a second the gauge recorded on September 11, 2026, are the reasons the water looks the same in September as in any other month.
Sources & data for this guide
- September air normals (88.1°F, 69.4°F, 5.05 in) and rain-day counts (6.9 days at 0.10 in, 1.4 days at 1 in) · NOAA NCEI monthly normals 1991-2020, station USW00012816, Gainesville Rgnl AP, FL US · checked Sep 24, 2026
- August and October normals (90.5/72.0/6.40 in/10.4 days and 82.1/60.6/2.68 in/4.0 days) · same NOAA NCEI 1991-2020 station record · checked Sep 24, 2026
- Station distance caveat: the thermometer sits about 78 km (roughly 48 miles) from the spring, and it measures air, not spring water · NOAA NCEI station metadata · checked Sep 24, 2026
- Sunrise 11:10 UTC and sunset 23:32 UTC on September 15, converted to local time, 12h 22m of daylight · sunrise-sunset.org · checked Sep 24, 2026
- Discharge of 87 cubic feet per second, instantaneous reading · U.S. Geological Survey, National Water Information System, station 02236160 Silver Glen Springs · read Sep 11, 2026
- Outstanding Florida Springs definition · Florida Statutes 373.802(5), leg.state.fl.us · checked Sep 24, 2026
- What we could not verify: no entrance fee, no opening hour and no manatee count. floridastateparks.org returned 403 to our automated reads and the FWC manatee pages render client-side · checked Sep 24, 2026
- Hurricane season dates and the September 10 peak are carried with their NOAA source on our Florida orientation page · checked Sep 24, 2026
To plan your stay
- Best Time to Visit Silver Glen Springs: Month-by-Month Weather, Rain Days and Daylight
- Silver Glen Springs in August: Weather, Rain Days, Crowds and a Two-Day Plan
- Silver Glen Springs in October: Weather, Rain Days and How It Compares to September
- Silver Glen Springs in July: Weather, Rain Days and How It Compares to June and August