# ERA5 t2m issue?

**URL:** <https://forum.ecmwf.int/t/era5-t2m-issue/2657>\
**Category:** C3S - Datasets and Usage\
**Tags:** era5\
**Created:** [3 May 2024 08:00 UTC](https://forum.ecmwf.int/t/era5-t2m-issue/2657 "2024-05-03T08:00:46Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![Jose\_maria\_Serra\_Diaz](https://forum.ecmwf.int/letter_avatar_proxy/v4/letter/j/a88e57/32.png) [@Jose\_maria\_Serra\_Diaz](https://forum.ecmwf.int/u/Jose_maria_Serra_Diaz)\
**Post date:** [3 May 2024 08:00 UTC](https://forum.ecmwf.int/t/era5-t2m-issue/2657/1 "2024-05-03T08:00:46Z")

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I downloaded two times in April and May netcdf data for ERA5 monthly t2m 1940-2023. The average global means seems to be way lower ranging from ~277 K to 279K over the yearly average time series, or 274.94 K 281.79 K for the monthly time series (without monthly averaging per year).

I tried redownloading the data, used Matlab and R and Panoply and different libraries to check for potential differences in reading the data, but I still get this low values. I also the same result with GRIBB datasets.

Is there an issue with the data ? or some offset/scale factor that I am not fully realizing. This is way lower than the published trends of global temperature.