Using Surf-Forecast’s Historical Surf Data To Find The Most Consistent Waves On Earth
Using our statistical data for 7000 spots dating back to 2006, we can find those waves that break the most, with the best winds.
Surf Forecasts:
Grandma's surfForecast / HAW – Maui / USA
48hr Weather and Surf, issued 7 am Saturday 20 Dec 2025 HSTForecast update in hr min s Forecast update imminent
Grandma's surf forecast is for near shore open water. Breaking waves will often be smaller at less exposed spots.
Today's Grandma's sea temperature is
25.9° C
(Which is 1.0°C warmer than normal for this time of year)How big are the waves at Grandma's today?
The current surf forecast for Grandma's at 10AM is: 0.3m 5s primary swell from a South direction (forecast issued at 07:00am December 20). An open ocean swell of 0.8m 11s is not directed at the surf break, a second open ocean swell of 0.4m 15s is not directed at the surf break. The wind direction is predicted to be cross-offshore.
| Time (HST) & Date | Wave Height | Wave Period |
|---|---|---|
| Morning (20 Dec) | 1.5ft (0.4m) | 5s |
| Afternoon (20 Dec) | 1ft (0.3m) | 5s |
| Evening (20 Dec) | 1ft (0.3m) | 16s |
Table - waves today at Grandma's. (Swell directed towards the surf break)
Updates in hr min s Forecast update imminent
Saturday 20 | Sunday 21 | Monday 22 | Tue 23 | |||||||||||||||||||||
| 5 AM | 8 AM | 11 AM | 2 PM | 5 PM | 8 PM | 11 PM | 2 AM | 5 AM | 8 AM | 11 AM | 2 PM | 5 PM | 8 PM | 11 PM | 2 AM | 5 AM | 8 AM | 11 AM | 2 PM | 5 PM | 8 PM | 11 PM | 2 AM | |
Rating (10 max) | ||||||||||||||||||||||||
Swell Height Map |    |    |    |    | ||||||||||||||||||||
| Wave Height (m) & direction (?) | ||||||||||||||||||||||||
| Period(s) (?) | 13 | 5 | 5 | 5 | 5 | 16 | 16 | 16 | 15 | 15 | 15 | 15 | 18 | 18 | 14 | 14 | 13 | 16 | 16 | 16 | 16 | 16 | 16 | 16 |
Wave (?)Graph  | ||||||||||||||||||||||||
 kJ (?) | 16 | 8 | 4 | 5 | 5 | 46 | 45 | 44 | 40 | 38 | 38 | 38 | 50 | 49 | 36 | 33 | 32 | 43 | 67 | 66 | 66 | 66 | 65 | 64 |
Wind (km/h) | ||||||||||||||||||||||||
| Wind State (?) onshore cross-onshore cross-shore cross-offshore offshore glassy | glass | cross- off | cross | cross | cross- off | off | cross- off | off | cross- off | off | glass | cross- off | off | off | off | cross- off | cross- off | off | glass | glass | glass | off | off | off |
High Tide / height (m) | 4:32AM 0.79 | 4:30PM 0.24 | 5:08AM 0.79 | 5:14PM 0.24 | 5:44AM 0.77 | 6:03PM 0.24 | ||||||||||||||||||
Low Tide / height (m) | 11:39AM 0.09 | 9:32PM -0.01 | 12:16PM 0.08 | 10:10PM 0.01 | 12:52PM 0.07 | 10:52PM 0.04 | ||||||||||||||||||
Saturday 20 | Sunday 21 | Monday 22 | Tue 23 | |||||||||||||||||||||
| Sunrise | - | 6:56 | - | - | - | - | - | - | - | 6:58 | - | - | - | - | - | - | - | 6:58 | - | - | - | - | - | - |
| Sunset | - | - | - | - | 5:49 | - | - | - | - | - | - | - | 5:50 | - | - | - | - | - | - | - | 5:50 | - | - | - |
 |  |  |  | |  | | | | | | | | | | | | | | |  |  | | | |
Rain (mm) | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - | 1 | 1 | 1 | - |
| Temp. °C | 25 | 25 | 27 | 27 | 26 | 24 | 24 | 24 | 24 | 24 | 26 | 27 | 27 | 24 | 24 | 24 | 23 | 24 | 26 | 26 | 25 | 24 | 23 | 23 |
| Feels °C (?) | 28 | 27 | 29 | 29 | 27 | 27 | 26 | 27 | 27 | 26 | 28 | 29 | 29 | 26 | 25 | 26 | 25 | 26 | 29 | 29 | 28 | 25 | 22 | 23 |
- Map Icons:
Break
Live Wave Height (m)
Live Wind Speed (km/h)
Surf Rating (10 Max)
Ocean Swells (m)- Wind Speed (km/h)
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