La Tranche-sur-Mer, France

1. Thu6 PM66°12 mph
2. 7 PM66°11 mph
3. 8 PM65°10 mph
4. 9 PM65°11 mph
5. 10 PM64°11 mph
6. 11 PM62°12 mph
7. Fri12 AM61°11 mph
8. 1 AM60°11 mph
9. 2 AM59°11 mph
10. 3 AM59°12 mph
11. 4 AM58°12 mph
12. 5 AM58°13 mph
13. 6 AM58°13 mph
14. 7 AM58°14 mph
15. 8 AM58°14 mph
16. 9 AM58°14 mph
17. 10 AM60°14 mph
18. 11 AM62°13 mph
19. 12 PM65°12 mph
20. 1 PM68°12 mph
21. 2 PM69°11 mph
22. 3 PM70°10 mph
23. 4 PM71°10 mph
24. 5 PM71°11 mph
25. 6 PM71°12 mph
26. 7 PM70°14 mph
27. 8 PM67°15 mph
28. 9 PM66°15 mph
29. 10 PM65°15 mph
30. 11 PM64°15 mph
31. Sat12 AM63°15 mph
32. 1 AM63°15 mph
33. 2 AM62°16 mph
34. 3 AM61°16 mph
35. 4 AM61°16 mph
36. 5 AM60°16 mph
37. 6 AM60°15 mph
38. 7 AM60°15 mph
39. 8 AM60°15 mph
40. 9 AM60°16 mph
41. 10 AM61°16 mph
42. 11 AM62°15 mph
43. 12 PM64°15 mph
44. 1 PM65°14 mph
45. 2 PM66°13 mph
46. 3 PM66°14 mph
47. 4 PM67°15 mph
48. 5 PM68°15 mph

Scroll sideways for more hours. Pick an hour for every number.

1. TodayOct 166°58°Mostly clear—wind 12 mph
2. FriOct 271°60°Partly cloudy—wind 15 mph
3. SatOct 368°60°Cloudy—wind 18 mph
4. SunOct 470°65°Partly cloudy—wind 17 mph
5. MonOct 571°68°Clear—wind 13 mph
6. TueOct 670°67°Cloudy—wind 16 mph
7. WedOct 767°60°Heavy rain showers—0.56 inwind 16 mph
8. ThuOct 861°53°Mostly clear—wind 19 mph
9. FriOct 960°59°Mostly clear—wind 15 mph
10. SatOct 1065°59°Rain—0.06 inwind 23 mph
11. SunOct 11~62°58°Model mean0.02 in
12. MonOct 12~63°58°Model mean0.02 in
13. TueOct 13~61°55°Model mean
14. WedOct 14~60°55°Model mean
15. ThuOct 15~62°58°Model mean0.28 in
16. FriOct 16~62°57°Model mean1.59 in

• Feels like66°
• WindNW 12 mph
• Humidity60%
• Dew point52°
• Pressure30.35 inHg
• UV index1 · Lowclear-sky peak 1 today
• Sunrise and sunsetSunrise · Sunset
• Moonrise10:07 PMMoonset 2:08 PM
• Moon phaseWaning gibbous76% lit

Each line is one model’s own forecast at its own grid cell: three kilometers for HRRR, a quarter of a degree for the global models, which can sit a few hundred meters above or below the town. Where they agree the forecast is settled; where they part is where it is not.

NWS gridGFSGEFS ± spreadECMWFECMWF AI

A ~ marks a high or low read from six-hourly steps, which miss the true extreme by a degree or two.

ECMWF ensemble meteogram

10 daysTemperature plume

None of these is a measurement. Each is a rating of the forecast ahead, and of what is happening at the point right now, against what the activity or the ailment is known to mind, and each names the figure that decided it. An ailment or a pest is rated as a risk, low to extreme; an activity, a chore or a journey as a condition, poor to ideal.

Each rating says which span it is for: the rest of today’s daylight, tonight, or the next 24 hours.

Tonight: 1 dark, clear hours without a bright moon, from 9:00 PM. Rated fair.

Dark is the sun 18 degrees below the horizon; where it never gets that low, 12 degrees, marked nautical. Clear is sky cover of 20% or less. A bright moon is one above the horizon with a quarter or more of its disc lit. Transparency in the table is estimated from surface humidity (70% and 85% mark fair and poor) and visibility, since the forecast carries no haze or high cloud moisture. Seeing and transparency by hour, where shown, are Environment and Climate Change Canada’s astronomy forecast (regional model; seeing from cloud, wind shear, turbulence near the ground and the surface temperature trend; transparency from the moisture through the whole air column), under the Open Government Licence - Canada. Dew is the air within 2 °C of its dew point. Excellent is four or more clear moonless hours with good transparency; good is three; fair is one, or two clear hours.

Golden hour is the sun between 6 degrees above the horizon and 4 degrees below it; blue hour is the sun between 4 and 6 degrees below. These are the definitions timeanddate.com and PhotoPills use. Directions are degrees clockwise from true north, where the sun’s upper edge and the moon’s center cross a flat horizon; hills and buildings change both. None means the sun does not reach that height on the day; all day means it stays inside the band.

Hours fit for spraying, and the days dry enough for fieldwork and hay, read from this forecast’s wind, gusts, humidity, temperature and rain.

Spraying windows

• Fri 3 PM to 5 PM 2 hours, every hour within the rules
• Mon 2 PM to Tue 2 AM 12 hours, every hour within the rules
• Fri 2 PM to 8 PM 6 hours, every hour within the rules
• Sat 2 AM to 8 AM 6 hours, every hour within the rules

Good Marginal No

Field days

Spraying: sustained wind 3 to 10 mph, the range US extension services and most labels give; gusts no more than 15 mph (this page’s limit); delta T (air minus wet-bulb temperature) 2 to 8 °C preferred and 8 to 10 °C marginal, from GRDC guidance, with the wet bulb by Stull’s formula; no hour at a 30% chance of rain or 0.25 mm forecast during the rain-free time. Follow the product label, which overrides all of this. Field days: dry is no daytime hour at a 30% chance and under 1 mm all day, wet is 6 mm (0.25 in) or more; soil moisture is not in the forecast, so ground still wet from earlier rain is not accounted for. Hay drying marks a dry day with humidity down to 50% and a breeze of 5 mph or more.

The best-rated day this week is Wednesday, rated good.

Periods in bold fall within an hour of sunrise or sunset. The weather’s side is the fishing index · Solunar tables for La Tranche-sur-Mer, by month

Major periods are two hours centered on the moon’s passage overhead and underfoot; minor periods are one hour centered on moonrise and moonset: the conventional durations of John Alden Knight’s solunar tables (1936). The rating is this site’s: one point to start, two more within a day and a half of a new or full moon (one more within three and a half days), and one more when a period falls within an hour of sunrise or sunset. The theory has mixed support in fisheries research; the times are exact astronomy.

1. Tonight58° · N 10–12 mph

   Mostly clear. Low near 15°C. North wind 16 to 20 km/h.

2. Friday71° · NE 9–14 mph

   Partly cloudy. High near 22°C. Northeast wind 15 to 22 km/h.

3. Friday Night60° · NNE 12–16 mph

   Partly cloudy. Low near 16°C. Northnortheast wind 19 to 26 km/h.

4. Saturday68° · NE 14–16 mph

   Cloudy. High near 20°C. Northeast wind 22 to 26 km/h.

5. Saturday Night60° · NE 15–18 mph

   Partly cloudy. Low near 16°C. Northeast wind 24 to 29 km/h.

6. Sunday70° · NE 12–17 mph

   Partly cloudy. High near 21°C. Northeast wind 20 to 27 km/h.

7. Sunday Night65° · NE 12–14 mph

   Partly cloudy. Low near 18°C. Northeast wind 20 to 22 km/h.

8. Monday71° · E 9–12 mph

   Clear. High near 22°C. East wind 14 to 19 km/h.

9. Monday Night68° · ENE 3–10 mph

   Partly cloudy. Low near 20°C. Eastnortheast wind 5 to 16 km/h.

10. Tuesday70° · SSE 12–16 mph

    Cloudy. High near 21°C. Southsoutheast wind 19 to 26 km/h.

11. Tuesday Night67° · WSW 11–11 mph

    Partly cloudy. Low near 20°C. Westsouthwest wind 17 to 18 km/h.

12. Wednesday67° · WSW 9–11 mph

    Heavy rain showers. High near 20°C. Westsouthwest wind 15 to 17 km/h. Precipitation around 14 mm.

13. Wednesday Night60° · N 16–19 mph

    Cloudy. Low near 16°C. North wind 26 to 30 km/h.

14. Thursday61° · NNW 16 mph

    Mostly clear. High near 16°C. Northnorthwest wind around 26 km/h.

15. Thursday Night53° · N 12–16 mph

    Clear. Low near 12°C. North wind 20 to 25 km/h.

16. Friday60° · N 7–11 mph

    Mostly clear. High near 16°C. North wind 12 to 18 km/h.

17. Friday Night59° · WNW 6–11 mph

    Cloudy. Low near 15°C. Westnorthwest wind 10 to 18 km/h.

18. Saturday65° · WSW 15–23 mph

    Rain. High near 18°C. Westsouthwest wind 24 to 37 km/h. Precipitation around 1.6 mm.

19. Saturday Night59° · NW 12–16 mph

    Clear. Low near 15°C. Northwest wind 19 to 25 km/h.

Climate of La Tranche-sur-Mer: normals, records and every month

The forecast office edits about sixty fields for every cell of its grid. The common ones are above; these are the rest, as the daily extreme, for anyone who needs the mixing height, the fire danger or the swell.