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Umatac surfForecast / Guam / Guam
12 Day Weather and Surf, issued 3 am Wednesday 16 Jul 2025 ChST
Best Forecast Surf Conditions for Umatac this week:
The surf forecast for Umatac over the next 12 days: The first swell (rated 1 star or higher) is forecast to arrive on Sunday (Jul 20) at 7AM. The primary swell is predicted to be 0.5m and 8s period. The wind is predicted to be glassy as the swell arrives.
The most powerful waves expected at Umatac in the next 12 days are 2.0m 12s and forecast to arrive on Wednesday (Jul 23) at 10AM. Winds are predicted to be offshore at the time the swell arrives. The largest open ocean swell (not directed at the beach) is 1.3m 10s period and expected on Thursday (Jul 17) at 10AM.
| Wave Type | Time (ChST) & Date | Wave Height & Period |
|---|---|---|
| Next good surf (1 star+) | 7AM (Sun 20th Jul) | 1.5ft (0.5m) 8s |
| Best Surf | 7AM (Wed 23rd Jul) | 6.5ft (2.0m) 12s |
| Most Powerful | 10AM (Wed 23rd Jul) | 6.5ft (2.0m) 12s |
Table - best surf conditions forecast for Umatac over the next 12 days.
Wednesday 16 | Thursday 17 | Friday 18 | Saturday 19 | Sunday 20 | Monday 21 | Tuesday 22 | Wednesday 23 | Thursday 24 | Friday 25 | Saturday 26 | Sunday 27 | |||||||||||||||||||||||||
| AM | PM | Night | AM | PM | Night | AM | PM | Night | AM | PM | Night | AM | PM | Night | AM | PM | Night | AM | PM | Night | AM | PM | Night | AM | PM | Night | AM | PM | Night | AM | PM | Night | AM | PM | Night | |
Rating (10 max) | ||||||||||||||||||||||||||||||||||||
Swell Height Map |  |  |  |  |  |  |  |  |  |  |  |  | ||||||||||||||||||||||||
| Wave Height (m) & direction (?) | ||||||||||||||||||||||||||||||||||||
| Period(s) (?) | 6 | 6 | 7 | 7 | 7 | 7 | 7 | 6 | 6 | 7 | 7 | 7 | 11 | 11 | 10 | 10 | 9 | 9 | 10 | 11 | 12 | 12 | 12 | 12 | 12 | 15 | 13 | 12 | 7 | 9 | 9 | 10 | 10 | 11 | 11 | 11 |
Wave (?)Graph  | ||||||||||||||||||||||||||||||||||||
| Energy (?) | 4 | 3 | 10 | 29 | 29 | 20 | 15 | 8 | 8 | 11 | 10 | 21 | 131 | 302 | 326 | 262 | 181 | 163 | 299 | 500 | 912 | 1142 | 1145 | 1020 | 1860 | 2510 | 1379 | 786 | 1157 | 2938 | 1931 | 1191 | 2253 | 2310 | 2756 | 3443 |
Wind (km/h) | ||||||||||||||||||||||||||||||||||||
| Wind State (?) onshore cross-onshore cross-shore cross-offshore offshore glassy | off | off | cross- off | off | off | off | off | off | cross- off | off | off | glass | glass | off | off | cross- off | cross- off | cross- on | cross | cross- on | cross- on | off | cross- on | on | cross | glass | cross- on | cross- on | cross- on | cross- on | cross- on | cross- on | cross | cross | cross- on | cross- on |
High Tide / height (m) | 10:47AM 0.61 | 12:10AM 0.74 | 12:07PM 0.56 | 12:42AM 0.74 | 1:44PM 0.53 | 1:17AM 0.74 | 3:37PM 0.55 | 1:58AM 0.73 | 5:21PM 0.61 | 2:47AM 0.73 | 6:38PM 0.67 | 3:43AM 0.73 | 7:35PM 0.72 | 4:42AM 0.74 | 8:21PM 0.75 | 5:41AM 0.74 | 9:01PM 0.76 | 6:37AM 0.74 | 9:36PM 0.76 | 7:29AM 0.73 | 10:08PM 0.75 | 8:19AM 0.71 | 10:36PM 0.73 | |||||||||||||
Low Tide / height (m) | 5:17PM 0.08 | 6:33AM 0.25 | 6:01PM 0.20 | 7:34AM 0.16 | 6:52PM 0.32 | 8:39AM 0.07 | 7:57PM 0.43 | 9:42AM -0.02 | 9:20PM 0.52 | 10:44AM -0.10 | 10:49PM 0.56 | 11:41AM -0.16 | 12:04AM 0.57 | 12:34PM -0.20 | 1:03AM 0.55 | 1:23PM -0.21 | 1:53AM 0.53 | 2:08PM -0.19 | 2:38AM 0.49 | 2:50PM -0.15 | 3:20AM 0.45 | 3:27PM -0.09 | ||||||||||||||
Wednesday 16 | Thursday 17 | Friday 18 | Saturday 19 | Sunday 20 | Monday 21 | Tuesday 22 | Wednesday 23 | Thursday 24 | Friday 25 | Saturday 26 | Sunday 27 | |||||||||||||||||||||||||
| Sunrise | 6:01 | - | - | 6:01 | - | - | 6:01 | - | - | 6:03 | - | - | 6:03 | - | - | 6:03 | - | - | 6:03 | - | - | 6:03 | - | - | 6:03 | - | - | 6:03 | - | - | 6:03 | - | - | 6:05 | - | - |
| Sunset | - | 6:52 | - | - | 6:52 | - | - | 6:52 | - | - | 6:52 | - | - | 6:51 | - | - | 6:51 | - | - | 6:51 | - | - | 6:51 | - | - | 6:51 | - | - | 6:51 | - | - | 6:50 | - | - | 6:50 | - |
 |  |  | |  | | | | | | | | |  | | |  |  | | |  | | | | | | | | | | | | | | | | |
Rain (mm) | 1 | - | 4 | - | 3 | 2 | - | 4 | 5 | 7 | 3 | 5 | 1 | - | 10 | 4 | 6 | 3 | 8 | 8 | 6 | 6 | 3 | 12 | 8 | 5 | 10 | 8 | 18 | 29 | 9 | 15 | 8 | 3 | 6 | 10 |
| Temp. °C | 29 | 29 | 29 | 28 | 29 | 28 | 29 | 29 | 28 | 28 | 28 | 28 | 28 | 29 | 28 | 28 | 26 | 28 | 28 | 28 | 27 | 26 | 26 | 27 | 28 | 28 | 27 | 27 | 26 | 27 | 27 | 26 | 28 | 29 | 28 | 28 |
| Feels °C (?) | 32 | 32 | 31 | 30 | 32 | 30 | 31 | 31 | 30 | 30 | 31 | 32 | 32 | 32 | 31 | 29 | 30 | 32 | 31 | 30 | 31 | 28 | 30 | 30 | 32 | 33 | 30 | 28 | 25 | 23 | 24 | 23 | 27 | 28 | 26 | 25 |
Short Range Forecast: Moderate rain (total 19mm), heaviest on Fri afternoon. Warm (max 29°C on Wed morning, min 28°C on Wed morning). Wind will be generally light. | Days 3-6 Weather Summary Heavy rain (total 39mm), heaviest during Sat morning. Warm (max 29°C on Sun afternoon, min 26°C on Mon afternoon). Wind will be generally light. | Days 6-9 Weather Summary Heavy rain (total 66mm), heaviest during Wed morning. Warm (max 28°C on Tue morning, min 25°C on Wed morning). Wind will be generally light. | Long Range Forecast: Heavy rain (total 107mm), heaviest during Fri afternoon. Warm (max 29°C on Sun morning, min 26°C on Fri afternoon). Winds increasing (moderate winds from the WSW on Fri morning, strong winds from the SW by Fri night). | |||||||||||||||||||||||||||||||||
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Ocean Swells (m)- Wind Speed (km/h)
Recent Eyeball Surf Reports for Guam
Continuing clean conditions at Umatac (calm at Windward Hills wx 13 km from Umatac). 0.1m 6s windswell from the W with a 0.1m 6s windswell from the W
2 h 36 min ago
FREE! Surf-Forecast.com widget for your website
The surf report / weather widget below is available to embed on third party websites free of charge and provides a summary of our Umatac surf forecast. Simply grab the html code snippet that we provide and paste it into your own site. You can choose your preferred language and metric/imperial units for the surf forecast feed to suit users of your site. Click here to get the code.
Information about the Umatac Surf forecast
The above surf forecast table for Umatac provides essential information for determining whether the surfing conditions will be good over the next 12 days. A general guide to surfing at Umatac can be found by selecting the local surf guide option on the grey menu. Our Umatac surf forecast is unique since it includes wave energy (power) that defines the real feel of the surf rather than just the height or the period. If you surf the same spot (Umatac) regularly then make a mental note of the wave energy from the surf forecast table each time you go. Very soon you may start to choose your surf days based on the wave energy alone combined with our forecast of favourable offshore wind conditions. Our star ratings will help here and of course you will also find the usual wave height and period predictions on our surf forecasts as well as a full break down of the swell components under our advanced users option (to reveal that, click the little Einstein character under the tide times).
Further information to help with frequently asked questions about our surf forecast for Umatac may be found under the help tab on the top menu and also by moving your mouse over the question marks on the surf forecast table itself. Please always bear in mind that the forecast is for near-shore open water and local factors at each surf break influence the actual breaking wave height, such as the beach / reef profile, water depths offshore and shelter.
Umatac is 22 km (14 miles) from Agana. If you plan a holiday in Guam, look for hotels and other accommodation in Agana. Agana has rooms for a wide range of budgets as well as car hire and transport links.
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