Five day forecast for Tryfan
| Fri 31st Jul | Weather | Temp. (C) | Feels like (C) | Rain Prob. (%) | Vis. | Hum. (%) | Wind Speed (mph) | Wind Gust (mph) | Wind Dir. | UV Index |
| 1200 | Partly cloudy | 19 | 11 | 0 | Very good | 66 | 36 | 47 | SSW | 7 |
| 1500 | Cloudy | 17 | 11 | 8 | Good | 80 | 31 | 40 | SW | 4 |
| 1800 | Cloudy | 13 | 7 | 14 | Moderate | 98 | 36 | 43 | SW | 1 |
| 2100 | Fog | 10 | 6 | 20 | Very poor | 100 | 31 | 36 | SW | 0 |
| Sat 1st Aug | Weather | Temp. (C) | Feels like (C) | Rain Prob. (%) | Vis. | Hum. (%) | Wind Speed (mph) | Wind Gust (mph) | Wind Dir. | UV Index | 0000 | Fog | 11 | 7 | 20 | Very poor | 100 | 25 | 29 | SW | 0 |
| 300 | Fog | 11 | 7 | 28 | Very poor | 100 | 22 | 27 | SW | 0 |
| 600 | Heavy rain | 11 | 8 | 83 | Very poor | 100 | 13 | 18 | W | 1 |
| 900 | Drizzle | 9 | 7 | 39 | Very poor | 99 | 11 | 16 | NW | 2 |
| 1200 | Fog | 9 | 6 | 24 | Very poor | 97 | 13 | 18 | WNW | 5 |
| 1500 | Sunny day | 9 | 6 | 2 | Excellent | 79 | 16 | 20 | W | 4 |
| 1800 | Mist | 8 | 5 | 15 | Poor | 94 | 13 | 20 | SW | 1 |
| 2100 | Mist | 8 | 4 | 19 | Poor | 98 | 22 | 27 | SW | 0 |
| Sun 2nd Aug | Weather | Temp. (C) | Feels like (C) | Rain Prob. (%) | Vis. | Hum. (%) | Wind Speed (mph) | Wind Gust (mph) | Wind Dir. | UV Index | 0000 | Heavy rain | 8 | 4 | 77 | Very poor | 99 | 18 | 22 | WSW | 0 |
| 300 | Fog | 7 | 3 | 23 | Very poor | 99 | 20 | 25 | W | 0 |
| 600 | Drizzle | 6 | 2 | 38 | Very poor | 98 | 20 | 27 | W | 1 |
| 900 | Mist | 7 | 3 | 35 | Poor | 96 | 16 | 22 | W | 3 |
| 1200 | Partly cloudy | 8 | 5 | 7 | Very good | 85 | 16 | 25 | W | 6 |
| 1500 | Cloudy | 9 | 6 | 7 | Very good | 77 | 13 | 22 | WSW | 4 |
| 1800 | Cloudy | 8 | 5 | 8 | Very good | 87 | 13 | 20 | SW | 1 |
| 2100 | Cloudy | 7 | 4 | 14 | Good | 95 | 11 | 18 | SSW | 0 |
| Mon 3rd Aug | Weather | Temp. (C) | Feels like (C) | Rain Prob. (%) | Vis. | Hum. (%) | Wind Speed (mph) | Wind Gust (mph) | Wind Dir. | UV Index | 0000 | Cloudy | 6 | 3 | 17 | Good | 97 | 9 | 13 | SSW | 0 |
| 300 | Cloudy | 5 | 3 | 17 | Moderate | 98 | 9 | 11 | S | 0 |
| 600 | Cloudy | 6 | 4 | 13 | Moderate | 98 | 7 | 11 | SW | 1 |
| 900 | Partly cloudy | 8 | 6 | 10 | Very good | 87 | 7 | 16 | W | 4 |
| 1200 | Light rain shower | 10 | 8 | 34 | Very good | 76 | 9 | 20 | WNW | 6 |
| 1500 | Partly cloudy | 10 | 8 | 12 | Very good | 72 | 11 | 22 | WNW | 4 |
| 1800 | Partly cloudy | 9 | 7 | 4 | Very good | 73 | 9 | 16 | WNW | 1 |
| 2100 | Cloudy | 6 | 4 | 6 | Very good | 93 | 7 | 11 | W | 0 |
| Tue 4th Aug | Weather | Temp. (C) | Feels like (C) | Rain Prob. (%) | Vis. | Hum. (%) | Wind Speed (mph) | Wind Gust (mph) | Wind Dir. | UV Index | 0000 | Cloudy | 5 | 3 | 6 | Very good | 96 | 9 | 11 | S | 0 |
| 300 | Cloudy | 5 | 2 | 8 | Good | 97 | 11 | 13 | S | 0 |
| 600 | Cloudy | 6 | 3 | 12 | Good | 97 | 13 | 20 | S | 1 |
| 900 | Cloudy | 8 | 4 | 24 | Moderate | 90 | 20 | 31 | SSW | 2 |
| 1200 | Heavy rain | 9 | 5 | 76 | Moderate | 90 | 22 | 40 | SSW | 4 |
| 1500 | Heavy rain | 10 | 6 | 79 | Moderate | 90 | 27 | 45 | SSW | 2 |
| 1800 | Light rain | 10 | 6 | 61 | Moderate | 95 | 29 | 45 | SSW | 1 |
| 2100 | Light rain | 10 | 5 | 63 | Poor | 97 | 29 | 47 | SSW | 0 |
Visibility - from the Met Office site
- Very poor - Less than 1km
- Poor - Between 1-4 km
- Moderate - Between 4-10 km
- Good - Between 10-20 km
- Very good - Between 20-40 km
- Excellent - More than 40 km
UV Index - from the Met Office site
The strength of the sun's ultraviolet (UV) radiation is expressed as a 'Solar UV Index', a system developed by the World Health Organization. These Met Office forecasts include the effects of:
- the position of the sun in the sky;
- forecast cloud cover;
- ozone amounts in the stratosphere.
The solar index does not exceed 8 in the UK (8 is rare; 7 may occur on exceptional days, mostly in the two weeks around the summer solstice). Indices of 9 and 10 are common in the Mediterranean area.
The UV Index can take the following values:
1-2 Low exposure. No protection required. You can safely stay outside
3-5 Moderate exposure. Seek shade during midday hours, cover up and wear sunscreen
6-7 High exposure. Seek shade during midday hours, cover up and wear sunscreen
8-10 Very high. Avoid being outside during midday hours. Shirt, sunscreen and hat are essential
11 or over Extreme. Avoid being outside during midday hours. Shirt, sunscreen and hat essential.
Weather forecasts courtesy of the Met Office.