Very low humidty levels

[scientist_uk]

Just curious, I noticed readings in the 20s percentage wise at a local weather station, I checked other stations accross the county of Essex and noticed the same . I thought low humidy reading this low were unheard of , lately its been around the 60 percent mark.. anyone have any ideas what is causing this ?

[Coast]

I've no idea, but not everywhere is as low as your observations at the moment:

 

 

Currently 48% here in Mid Sussex and 54% back home on the coast:

 

http://www.weathershop.co.uk/our-weather/weatherdisplaylive

 

 

 

 

[4wd]

It changed yesterday as the wind went more to NW, very good for drying hay out I have found, with almost no dew this morning.That 20% sounds suspiciously low, some of the home stations do read very low and give silly dewpoints as a result.It's been around 50% here but an Oregon set not far away says 33%.At 20% dewpoint could be near freezing even though it's above 20C. 

[Bottesford]

33% here (temp 24.7c d.p. 7.2c). Quite dry yes.

[scientist_uk]

ya sorry i meant in the 30s but im seeing around 31 percent and im on the coast in southend, temps already matched yesterday and its not even solar noon, ive checked these same stations for days and they usually read 55-60ish, no chance of a storm then but some lovely bits cirrus knocking around

Edited July 15, 2013 by scientist_uk

[Alex]

Southend-on-sea was registering 27c and 20% humidity at 12:00! I've seen a bit lower before in Essex and 15-25% isn't that uncommon.

[chionomaniac]

Remember that as the temperature soars during the heat of the day the relative humidity drops inversely even though the dew point may be fairly constant. Today is a classic case in point as my screen shot of my weather station data shows.

 

The blue line shows how the relative humidity has dropped as the outside temp has increased (yellow line) whist the dew point has only reduced slightly:

 

[summer blizzard]

Probably a comibination of wind direction and high pressure, won't last long though as we look to increase humidity through the week.

 

At my parents i did notice that humidity was around 70% on Saturday but had dropped below 40% yesterday.

[Jax]

all makes sense, my outside sensor is not talking to me anymore, the indoor one says 20%

[Relativistic]

My personal weather station is currently reading 40% humidity here in Chelmsford. I have no idea how accurate this is though!

[scientist_uk]

27.4 degrees as long as that wind keeps nudging north-west 28 is very possible pretty damn hot but at 34percent humidty it feels quite nice , amazing hoe much difference humidty effects how hot we feel, i, just concerned about my fruit setting on the tomato plants but im sure humidty will shoot up this evening as it cools off.

[Nick.F]

41% Essex/Suffolk borders

[scientist_uk]

27.4 degrees as long as that wind keeps nudging north-west 28 is very possible pretty damn hot but at 34percent humidty it feels quite nice , amazing hoe much difference humidty effects how hot we feel, i, just concerned about my fruit setting on the tomato plants but im sure humidty will shoot up this evening as it cools off. as i write its jumped to 27.8!

[Polar Maritime]

Currently 50% here..

 

Past 12 hrs

 

 

[Evening thunder]

About 55% here with a dew point of 14-15c, This morning, yesterday and the day before had a dew points around 18c much of the time so quite humid for us.

 

However one day last week we had the humidity go down to 25%, which is the lowest I've recorded in nearly 6 years of data and gave a dew point of 4.9c when the temp was 26.6c. 

 

Looking at xcweather there's some quite low humidity in the SE though, 21% at Heathrow and 19% at London City Airport

[ARW WeatherMan]

Just mentioned this in the current "settled spell discussion"! It is currently 27.2oC and 32% humidity here and it has reached 28.7oC here today with a humidity of 27% and I have just glanced through my 4 year of records and the lowest I happened to see was the low 30%'s a few times and so I believe today could be the driest air I have ever recorded here!

[4wd]

all makes sense, my outside sensor is not talking to me anymore, the indoor one says 20%

One of the problems this time of year here is high indoor humidity with no heating on and windows generally open.In winter it's not a problem but at this time of year I keep my SLR and lenses in a box with moisture absorbing sachet things you can heat to re-use.If stored at humidities above 50% fungus can form internally on lenses and it's very difficult to remove.I've seen it touch 70% on occasion.Lowest humidity here is usually in March or April, I think the lowest recorded was 23% (VP2)This will generally be with a dry but chilly North-Westerly flow of Arctic origin.

[richie3846]

I have noticed this year in particular there has been a trend toward very low humidity levels in the 20% to 40% range. Even when it was cold in the spring! I think this has something to do with the regular east wind we have been experiencing. Not an expert, just a guess.