Monthly Evapotranspiration Rate

I was using the online database at http://wcatlas.iwmi.org/Default.asp with success recently. This was giving same figures as another source for one specific project. The source of ET0 was not asked for, but I think the database above is actually stated somewhere in the reference guide (maybe online).

I would not claim that it is authorised but it should certainly be ok. Actually, I can't find a reference to the site in any reference guide. But I used it just weeks ago for a V3 design submission, I named the site as data source and there was no comment on that in the review. LEED V4 reference guide states "Evapotranspiration data are available through various government and academic sources. ". So it should be ok.

V4 also links to the FAO site, I assume they mean this calculator: http://www.fao.org/land-water/databases-and-software/eto-calculator/en/. I did not use it, can't remember why.

Hi Jens 

We're looking at using the same reference site to collect ETo rates for a project in KSA, but found the website provided ETo (mm/day) and not as ETo (mm/month) as per the LEED 'Baseline Caculation' tab in the LEED v4 Outdoor Water Use Reduction Calculator. How did you convert this to monthly rates?

I'm following up on this thread for the approach used to convert ETo from mm/day to mm/month, or is the conversion even required?

Hi Senna and Priscilla,

You can convert the ETo (mm/day) by multiply with numbers of day in each month to get ETo (mm/month). So for example in January, you got ETo (mm/day) from the http://wcatlas.iwmi.org/Default.asp , then multiply with 31 (because there are 31 days in January) then fill up the form with this result (mm/month).

Thanks