Hello. I would like to download the ERA5 land monthly averages — I see there is an option to download the “hourly” monthly average, which I assume means the 00Z, 01Z, etc. average across all of the 00Z, 01Z,… etc. values for that month (e.g., Jan. 1950)
This is exactly what I want for my application.
BUT—
It looks like I only see the 0th hour when I select this option? Here is a minimum api request:
import cdsapi
dataset = “reanalysis-era5-land-monthly-means”
request = {
“product_type”: [“monthly_averaged_reanalysis_by_hour_of_day”],
“variable”: [“2m_temperature”],
“year”: [“2023”],
“month”: [“01”],
“time”: [
“21:00”, “22:00”,
],
“data_format”: “netcdf”,
“download_format”: “unarchived”,
“area”: [90, -180, -90, 180]
}
client = cdsapi.Client()
client.retrieve(dataset, request).download()
~
~
~
I would expect to see the 21 and 22 hours in the file. But i only see the following time in the resultant nc file —
- array([‘2023-01-01T00:00:00.000000000’], dtype=‘datetime64[ns]’)
There’s only 1 time and it appears to be at 00Z.
Any ideas? Am I understanding this download option correctly? Can someone else try this and confirm they are seeing the same thing? Is this the expected behavior?
THanks!
Hi William, are you looking for the dataset “ERA5-Land hourly data from 1950 to present”? (ERA5-Land hourly data from 1950 to present) The dataset you selected only provides the monthly averaged data. By the way, I’m wondering what the difference is between “Monthly averaged reanalysis” and “Monthly averaged reanalysis by hour of day” in the dataset “ERA5-Land monthly averaged data from 1950 to present”? Thank you very much!
If you go to the download page for " ERA5-Land monthly averaged data from 1950 to present" then there is an option to select “Monthly averaged reanalysis by hour of day” shown below —
So I assume this data is part of this dataset. But, my problem is that this download option does not appear to produce what it says. Maybe this data isn’t actually present — if this is the case, the download option should be removed to avoid confusion.
I still have not resolved this issue! Thanks
Hello – maybe someone will find this post in the future.
The downloader does work if you select ‘monthly averaged reanalysis by hour of day’-- you just cannot specify more than one hour at a time!
I have verified that when I select just one hour (00Z for example) that the resulting monthly averaged file (Jan 2020 for example) is in fact different than selecting 12Z .
Ideally the metadata information would include the hour that you’ve downloaded, but it dos not. I also think there should be some additional description in the downloader tool to tell you this.
Regardless, I’m really glad that this data is avaialable this way since it makes myh life much easier! Thanks !
