As dry as we wanna be

It borders on the impossible, in fact, for things to get much drier than this:

On Tuesday afternoon at 12 UTC on June 20, 2017, the temperature at Safi-Abad Dezful, Iran hit 115.7°F (46.5°C) with a -27.8°F (-33.2°C) dewpoint, giving this city of 420,000 in western Iran a ridiculously low relative humidity of 0.36%. At that level of atmospheric moisture, the temperature would have had to plunge 143°F (80°C) in order for the moisture to condense out and form ground-level clouds. If one were to cry in joy (or more likely) in despair at the heat, I doubt those tears would reach your lips!

I asked weather records expert Maximiliano Herrera about the reading, and he stated that he confirmed the validity of the reading with Iranian meteorologist Sabit Siddiqi. This was the lowest humidity in world recorded history that Herrera was aware of; the previous lowest humidity he knew of was in Las Vegas, Nevada: a 0.6% reading on June 27, 2011.

There’s apparently one more reading in this ballparK:

[O]n May 4, 2014, Needles, California hit 102°F (38.9°C) with a -36°F (-38°C) dewpoint, which works out to a relative humidity of 0.33%. Given that we can’t really measure humidity to a precision of hundreths of a percent, the two readings are pretty much tied for the lowest humidity record.

And going in the other direction:

A dew point of 35°C (95°F) was observed at Dhahran, Saudi Arabia, at 3:00 p.m. on July 8, 2003.

God bless you, Willis Carrier.


  1. McG »

    23 June 2017 · 11:05 am

    There was many a winter day in Fairbanks, when we lived there, that neither The Weather Channel nor any of the local weathercasters had a dewpoint to report. Apparently there are temperatures below which a dewpoint simply couldn’t be calculated.

  2. fillyjonk »

    23 June 2017 · 11:14 am

    Safi-Abad Dezful is welcome to some of the 73 degree dewpoint sponginess we had here today.

    even the half-hour of research-plot maintenance work I had to do outside was deeply unpleasant.

  3. CGHill »

    23 June 2017 · 11:16 am

    Probably around 40 below; there is a valuation set in general use that starts at -40°C.

  4. fillyjonk »

    23 June 2017 · 11:16 am

    Also, I have been told a dewpoint above 95 F is incompatible with human life. I would not be inclined to doubt that.

  5. Holly H »

    23 June 2017 · 12:36 pm

    I don’t know how I lived without my home humidifier until this year. I had constant skin fissures and nosebleeds, but didn’t get a clue until my son mentioned how dry it is in my house. So now I am ‘born again’ and constantly spread the word about how great they are.

  6. In The Mailbox: 06.23.17 : The Other McCain »

    23 June 2017 · 5:12 pm

    […] Dustbury: As Dry As We Wanna Be […]

  7. CGHill »

    23 June 2017 · 5:29 pm

    My house stays at 40 to 55 percent ten months out of the year. In Deep Winter, I do need help.

  8. fillyjonk »

    23 June 2017 · 5:48 pm

    I have to have both a humidifier (for winter) and a dehumidifier (for summer). Part of that is I have an old piano I am trying to keep in tune but when it’s spring, and still too cool to run the AC, I’ve seen the humidity spike up to near 60% in the house.

    and it feels better to me if I can keep it down around 40, though 45 is the best I can get most days.

    I barely had to run the humidifier this past winter, though.

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