Warmer in the evening

karlitob

Hi all

Query.

Over the last few years, I’ve noticed that the warmer part of the day is from 3-6 in summer. Spent a lot of time in the garden working during the summer over the past few years - serious manual stuff and midday is not hotter than 4 pm. Find this when not working also.

Am I imagining it. Always thought midday was the hottest. In Dublin if that makes a difference.

Comhrá

Probably due to the ground absorbing the sun's heat over the daylight hours, then gradually radiating the stored heat back into the atmosphere in the evening and into early night.

tom1ie

karlitob wrote: »

Hi all

Query.

Over the last few years, I’ve noticed that the warmer part of the day is from 3-6 in summer. Spent a lot of time in the garden working during the summer over the past few years - serious Manila stuff and midday is not hotter than 4 pm. Find this when not working also.

Am I imagining it. Always thought midday was the hottest. In Dublin if that makes a difference.

I've definitely noticed this.
I have a raised bed with a hinged poly tunnel on it, generally it's much warmer at 3-4 then 12 but as mentioned above that's probably a cumulative effect from throughout the day.
Still though I reckon and plenty of farmers I speak to reckon it's hotter later in the day.

cap.in.hand.

karlitob wrote: »

Hi all

Query.

Over the last few years, I’ve noticed that the warmer part of the day is from 3-6 in summer. Spent a lot of time in the garden working during the summer over the past few years - serious Manila stuff and midday is not hotter than 4 pm. Find this when not working also.

Am I imagining it. Always thought midday was the hottest. In Dublin if that makes a difference.

High density housing in a area captures and releases heat from the sun into the evening too.

ForestFire

Few points to consider...

Summertime moves the clocks forward one hour, so midday is technically at 1 o'clock....and looking at some websites the sun is at its highest point today at 1:29.

Add to this the lag in time to heat the atmosphere, earth from this point puts the hottest time of the day after this point

Not sure what this lag is but looking at today's temperature 3 to 5 is the hottest time of the day.

karlitob

Thanks everyone. I had considered the actual zenith versus the time must be different. But forgot about the land heating. Kinda like the effect of the land sea breeze when out sailing - kinda.

Very good. At least I’m not imagining it. Thanks.

JCX BXC

You'll generally find that the hottest part of the day is around 4-5pm during a spell of sunny weather, as the ground heats up during the day.

A similar pnenomon at night, coldest part of the night is normally just before sunrise as the ground continues to cool, this also assists in keeping the early part of the day cool when the sun does rise.

Gaoth Laidir

This is a graph of hourly temperature at Claremorris over the past two days, clearly showing the peak in the mid-afternoon due to the cumulative effect described above. I note that in sunny weather in the summer, Shannon normally has its maximum a little later, around 5-6 pm, and doesn't really start to cool down until after 9 pm..

Regarding the coldest time, it is actually just after sunrise, not before it. That gives the maximum time for cooling before the sun actually gets high enough to start to warm things up.

Oneiric 3

Just to complient GL's chart above, this is the average hourly temp at Claremorris for July, based on hourly readings since 1986:

(a shockingly bad chart as rushed)



On average, temps will peak around 4pm, which I find surprising, given that summer temps, as the original poster notes, tend to peak more around 5 or 6pm here not too far from that station, but that would be more during weather like this rather than more typical westerly weather.

For what it is worth, hourly April averages are not too dissimilar. (in terms of peak/trough timing)


I will do up some similar stats for Dublin later just to compare and to see if there is any difference between west and east.


All data above from Met.ie

Supercell

Another factor to consider is sea breeze if you are close to the coast. I'm about one km from the sea here (Loughlinstown in south Dublin) and oftentimes in summer when the sea breeze dies off around 5 or 6 in the evening the temperature shoots up. Its very noticeable especially if the prevailing wind is light westerly or southwesterly.

Oneiric 3

Casement hourly stats since 1991 (I can't find older file which goes back to 1986 ) Table shows hourly mean for the 4 months in question and the absolute hourly max and min that were recorded during this 30 year time period.



Data from Met Eireann.