NOAA station analysis · local station time
Portland, Maine Tide Range: Which Dates Have the Largest Spread?
Which Portland, Maine dates have the largest NOAA-predicted tide range over the next 30 days?
The answer
From September 29, 2026 through October 28, 2026, Portland, Maine's largest listed NOAA turn-to-turn range is 12.403 ft (3.780 m converted) on October 28, 2026. The smallest listed range is 6.131 ft (1.869 m converted) on October 19, 2026.
Across the 30 local dates, NOAA returned 4 dates with 3 listed turns (13%), 26 dates with 4 listed turns (87%). The page preserves those returned counts; it does not add a tide event where the official response supplied none.
How this calculation works
For each local date, this page subtracts the lowest listed NOAA high/low prediction from the highest listed prediction. NOAA supplies feet relative to Mean Lower Low Water (MLLW); metres are conversions from those official feet values.
A listed prediction range is not observed water depth, launch clearance, or a safety guarantee. Wind, pressure, storms, and local conditions can make observed water different.
30-day NOAA station sequence
| Local date | Listed turns | Lowest turn | Highest turn | Computed range |
|---|---|---|---|---|
| 2026-09-29 | 4 | 19:40 · -0.750 ft | 13:19 · 10.706 ft | 11.456 ft (3.492 m) |
| 2026-09-30 | 4 | 20:28 · -0.627 ft | 14:03 · 10.695 ft | 11.322 ft (3.451 m) |
| 2026-10-01 | 4 | 21:22 · -0.351 ft | 14:53 · 10.516 ft | 10.867 ft (3.312 m) |
| 2026-10-02 | 4 | 22:22 · -0.017 ft | 15:50 · 10.229 ft | 10.246 ft (3.123 m) |
| 2026-10-03 | 4 | 23:28 · 0.259 ft | 16:55 · 9.942 ft | 9.683 ft (2.951 m) |
| 2026-10-04 | 3 | 11:42 · 1.231 ft | 18:05 · 9.755 ft | 8.524 ft (2.598 m) |
| 2026-10-05 | 4 | 00:37 · 0.384 ft | 19:17 · 9.727 ft | 9.343 ft (2.848 m) |
| 2026-10-06 | 4 | 01:47 · 0.315 ft | 20:25 · 9.849 ft | 9.534 ft (2.906 m) |
| 2026-10-07 | 4 | 02:49 · 0.113 ft | 21:25 · 10.014 ft | 9.901 ft (3.018 m) |
| 2026-10-08 | 4 | 03:42 · -0.079 ft | 22:18 · 10.108 ft | 10.187 ft (3.105 m) |
| 2026-10-09 | 4 | 16:54 · -0.290 ft | 10:43 · 10.120 ft | 10.410 ft (3.173 m) |
| 2026-10-10 | 4 | 17:41 · -0.466 ft | 11:27 · 10.323 ft | 10.789 ft (3.288 m) |
| 2026-10-11 | 3 | 18:24 · -0.468 ft | 12:07 · 10.358 ft | 10.826 ft (3.300 m) |
| 2026-10-12 | 4 | 19:06 · -0.308 ft | 12:46 · 10.240 ft | 10.548 ft (3.215 m) |
| 2026-10-13 | 4 | 19:47 · -0.015 ft | 13:24 · 9.998 ft | 10.013 ft (3.052 m) |
| 2026-10-14 | 4 | 20:29 · 0.367 ft | 14:03 · 9.673 ft | 9.306 ft (2.836 m) |
| 2026-10-15 | 4 | 21:13 · 0.778 ft | 14:45 · 9.309 ft | 8.531 ft (2.600 m) |
| 2026-10-16 | 4 | 22:03 · 1.152 ft | 15:32 · 8.956 ft | 7.804 ft (2.379 m) |
| 2026-10-17 | 4 | 22:56 · 1.424 ft | 16:25 · 8.672 ft | 7.248 ft (2.209 m) |
| 2026-10-18 | 4 | 23:52 · 1.553 ft | 17:22 · 8.502 ft | 6.949 ft (2.118 m) |
| 2026-10-19 | 3 | 12:01 · 2.335 ft | 18:20 · 8.466 ft | 6.131 ft (1.869 m) |
| 2026-10-20 | 4 | 00:47 · 1.526 ft | 19:17 · 8.565 ft | 7.039 ft (2.145 m) |
| 2026-10-21 | 4 | 01:40 · 1.351 ft | 20:12 · 8.783 ft | 7.432 ft (2.265 m) |
| 2026-10-22 | 4 | 02:28 · 1.071 ft | 21:01 · 9.073 ft | 8.002 ft (2.439 m) |
| 2026-10-23 | 4 | 15:35 · 0.598 ft | 21:47 · 9.376 ft | 8.778 ft (2.676 m) |
| 2026-10-24 | 4 | 16:18 · -0.034 ft | 10:06 · 9.874 ft | 9.908 ft (3.020 m) |
| 2026-10-25 | 4 | 17:02 · -0.588 ft | 10:45 · 10.415 ft | 11.003 ft (3.354 m) |
| 2026-10-26 | 3 | 17:46 · -0.997 ft | 11:25 · 10.845 ft | 11.842 ft (3.609 m) |
| 2026-10-27 | 4 | 18:32 · -1.210 ft | 12:08 · 11.117 ft | 12.327 ft (3.757 m) |
| 2026-10-28 | 4 | 19:21 · -1.205 ft | 12:55 · 11.198 ft | 12.403 ft (3.780 m) |
Source and reproducibility
Source: NOAA CO-OPS Tide Predictions API, station 8418150, request 2026-09-29 through 2026-10-28, MLLW, station local time, English units.