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Does it rain more often on weekends than weekdays?

I don't remember where I heard this, but due to human activity such as

  1. Factories not opening on weekends
  2. Fewer people traveling in cars
  3. Offices closed so air conditioning is less utilized
  4. etc...

Does this have an effect on the weather from day to day anywhere in the world?

Sklivvz
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Mark Price
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1 Answers1

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Apparently, "yes", according to

Weekly cycles of air pollutants, precipitation and tropical cyclones in the coastal NW Atlantic region. R.S. Cerveny and R.C. Balling, Jr. Nature, 394: 561-562. 1998 (www)

Abstract: Direct human influences on climate have been detected at local scales, such as urban temperature increases and precipitation enhancement[1], [2], [3], and at global scales[4], [5]. A possible indication of an anthropogenic effect on regional climate is by identification of equivalent weekly cycles in climate and pollution variables. Weekly cycles have been observed in both global surface temperature[6] and local pollution[7] data sets. Here we describe statistical analyses that reveal weekly cycles in three independent regional-scale coastal Atlantic data sets: lower-troposphere pollution, precipitation and tropical cyclones. Three atmospheric monitoring stations record minimum concentrations of ozone and carbon monoxide early in the week, while highest concentrations are observed later in the week. This air-pollution cycle corresponds to observed weekly variability in regional rainfall and tropical cyclones. Specifically, satellite-based precipitation estimates indicate that near-coastal ocean areas receive significantly more precipitation at weekends than on weekdays. Near-coastal tropical cyclones have, on average, significantly weaker surface winds, higher surface pressure and higher frequency at weekends. Although our statistical findings limit the identification of cause–effect relationships, we advance the hypothesis that the thermal influence of pollution-derived aerosols on storms may drive these weekly climate cycles.

Via the BBC. Citing papers here, (via Google scholar), some of which seem to provide other examples of similar phenomena. My experience as a keen cricketer also suggests there may be some substance to this idea :-(

However, also perhaps "no", according to

David M. Schultz, Santtu Mikkonen, Ari Laaksonen and Michael B. Richman, "Weekly precipitation cycles? Lack of evidence from United States surface stations", Geophysical Research Letters, Vol 34 Issue 22, 2007, (www)

1 Previous work has inferred a relationship between human activity and the occurrence and amount of precipitation through examining possible weekly cycles in precipitation. Daily precipitation records for 219 surface observing stations in the United States for the 42-year period 1951–1992 are investigated for weekly cycles in precipitation. Results indicate that neither the occurrence nor amount of precipitation significantly depends upon the day of the week.

Glorfindel
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    I think the difference is that the study that found no difference was looking at weather stations at various cities, while the study that did find differences was looking at off-shore areas: *"The region just off the heavily populated east coast of the US was soaked at weekends."* Of course probably only mariners care if it's rainier off-shore on weekends. – Gabe Jul 05 '14 at 05:58
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    I suspect there is also the issue of multiple hypothesis testing, if you look at lots of datasets to find a statistically significant correlation, you will generally be able to find one, even when **all** of the correlations are spurious. What is needed are observations that confirm the physical mechanism purported to explain the correlation. The fact that the first paper only has about 150 citations, and most of them are not actually following up the work, suggests that this has not been that unusual or important research finding, but interesting nevertheless. –  Jul 05 '14 at 09:06
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    I've asked the met office if they will provide statistics – Mark Price Jul 07 '14 at 19:44
  • I'd be very interested to hear if there is any good data on this for the UK. –  Jul 08 '14 at 16:04
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    Yes and no. It doesn't change the larger systems that bring weather, but it does affect localised falls. So it would depend where you are measuring as to whether that would affect local weather. – Tim Scanlon Jul 09 '14 at 03:30