Harrow on the Hill walk

Met Office Forecast

South East England

Rather cloudy and damp today. Less cold than on Tuesday.

Today:

Rather cloudy and damp today, with some patchy light rain and drizzle at times, especially first thing. Perhaps the occasional brighter interlude into the afternoon. Feeling less cold than on Tuesday. Turning cloudier from the west later in the day. Maximum Temperature 11C.

Tonight:

A band of rain, heavy at times, will move northeastwards across all parts during the evening and overnight. Winds freshening. Less cold than previous nights. Minimum Temperature 7C.

Thursday:

The band of rain, heavy at times, will continue to slowly move northeastwards during Thursday, gradually easing as it does so. Becoming drier later in the day. Feeling much milder. Maximum Temperature 13C.

Outlook for Friday to Sunday:

Rain gradually sinking back southwards on Friday. Turning colder, with widespread frost overnight. Dry, sunny and cold on Saturday and early Sunday, before cloud and rain arrives later.

Day 6-7 and Week 2:

After a very cold but bright start to Sunday, rain will move in from the west later. Going into next week, unsettled conditions look likely to dominate, with low pressure systems moving in off the Atlantic. The weather will be changeable. Periods of rain or wintry showers, and strong winds are likely, especially in the west, with brief more settled spells in between. Westerly or southwesterly winds during this period will bring milder temperatures to most areas, but occasional interludes of cold northerly winds are possible. It will be on this boundary between colder and milder airmasses where any snowfall to lower levels could possibly occur. Towards the end of this period, we may see high pressure build over the north of the UK, bringing colder temperatures and wintry outbreaks.

Week 3 and 4:

Although confidence at this range is low, current signals suggest that high pressure could be positioned over the north of the UK during this period. This would likely bring wintry outbreaks and colder than average temperatures to northern areas, as well as increasing the likelihood of more widespread cold spells. Any periods of milder, unsettled weather are more likely to be confined to central and southern areas, where greater than average rainfall is predicted. There is a continued risk of significant snowfall events on the boundary between colder and milder airmasses, with snow possible to low elevations.

Met Office : South East England : 2021-01-27T01:56:10

Daylight : London

Day length is dusk to dawn. Times will vary a little if there is a hill on the horizon.

It should still be light enough to read at dawn and dusk, so there will be enough light for walking even earlier (later).

Moonlight : London

Notes

• The moon's phase or fracillum (percentage of the moon illuminated) doesn't vary much with location.
• A full moon is not just bigger, its much brighter. A half moon ('50%') give less than 5% of the illumination of a full moon. You can walk with a half moon if its high in the sky (after dusk for a growing moon, before dawn for a shrinking moon).
• Sky glow (light reflected by air or clouds) from nearby cities, and especially snow on the ground also effect light levels.
• Times will vary a few minutes, as (i) these figures are for the centre of the county the walk is in, (ii) if there are hills on the horizon, and (iii) if you are on a hill
• Of course, you need a cloudless night as well!