[Q] How to generate daily weather data?



Can someone tell me how to generate daily weather data from an historical daily meteorological data using DSSAT (WeatherMan)?



In order to generate daily weather data you require climate data as input. WeatherMan has the capability to create the climate data if you import at least 5 to 10 years of daily weather data. Once you have created the climate data file with WeatherMan there is a separate option to generate daily weather data and then to export the files.In DSSAT you need to select externally generated weather data in the simulation controls in order for the model to find the data.

About Gerrit Hoogenboom

Professor, University of Florida

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  1. Amir
    April 17, 2014 at 11:18 am #

    Hi all

    where can I download the weatherman for win 64 bit?


    • Jawoo Koo
      April 20, 2014 at 9:24 am #

      WeatherMan should work fine for the 64-bit Windows. Note that the WeatherMan is part of DSSAT (you can request to download DSSAT from http://dssat.net/downloads. Let us know if you find any error message.

  2. Name (required)
    January 16, 2015 at 4:37 pm #

    I’ve imported six years of daily weather data into Weatherman which includes radiation, max and min temperature, precipitation, and windrun. I am able to correct missing values for all parameters lest windrun. Does anyone know how to correct missing windrun data?

    Thanks in advance,

    Mike B.

  3. Name (required)
    October 25, 2016 at 1:59 pm #

    For a growing season of canola (around 5 months); is that okay if I choose 4 weeks (before and after)as weather records data to perform “What-if” analyses??? or Do I need more???


    • Gerrit Hoogenboom
      March 3, 2017 at 8:25 am #

      Very good question. It depends somewhat on your “what-if” analysis. If you are planning to change planting dates, you need to make sure that you have sufficient data to cover your planting date range for your analysis. If you are planning to change your variety, a longer season variety could require more weather data.

    • Name (required)
      March 28, 2017 at 3:01 am #

      I have 50 years of historical weather and I want to generate weather from today until the end of the season to estimate a range of probable yields for my on-going season. How much years should I generate to have a good estimation? I see quite often 30 years generation, but I dont know the reason for such number. Would the estimation be better as much years are generated?


      • Gerrit Hoogenboom
        March 28, 2017 at 11:22 am #


        If you have 50 years of weather data available I would use all 50 years to complete your weather data from today until the end of the season. I suggest that in this case you do not use the weather generator as you have a very good historical data set. You might also want to consider looking at the Weather Analogue program. It will check your 50 years of historical weather data and select the year that is most similar to your current weather data. It will also fill your weather file with the data from the analogue year.

  4. Maria
    March 3, 2017 at 4:06 am #


    Once I have generated daily weather data with the weatherMa tool, How can I create different weather scenarios?

    • Gerrit Hoogenboom
      March 3, 2017 at 9:03 am #

      The weather generator in WeatherMan can only generate different sequences of daily weather data. Once you have generated them within WeatherMan, you need to export the generated weather data similar to exporting observed data. Select File, Save Station and then the Generated Data Tab.

  5. Ranjeet Jha
    April 7, 2017 at 4:39 pm #


    In weather data inputs, relative humidity is not the necessary requirement, right? If I am doing the analysis for future climate change, so I have Solar radiation, Precipitation, minimum and maximum temperature from GCMs simulation. So, I was just wondering that these should be sufficient for DSSAT simulation, right?



    • Gerrit Hoogenboom
      April 11, 2017 at 4:29 pm #

      DSSAT requires daily maximum and minimum temperature, solar radiation, and precipitation as input.



  6. Joy
    September 12, 2017 at 2:48 am #

    If I have ran climate data from global model CESM, how could I transfer it into file forms that DSSAT needs.

    • Gerrit Hoogenboom
      September 12, 2017 at 9:29 am #

      DSSAT requires daily weather data as input. You can use the Environmental Modification section if you Delta climate change equivalent data. Otherwise you can use one of the weather generators if you have all the climate input data required for the weather generator.



      • Joy
        September 13, 2017 at 3:19 am #

        Sorry, I’m new to DSSAT. What’s Environmental Modification section? And could you recommend any weather generator?

  7. Name (required)
    July 31, 2018 at 3:58 am #

    i have a historical weather data of 30 years and future data about 90 years how can i import data is DSSAT is it only one file. combine past plus future and what step i have to be done to import in DSSAT. All data is available in excel file.

    • Gerrit Hoogenboom
      August 19, 2018 at 10:12 pm #

      WeatherMan is the best tool for importing observed data in Excel format and then exporting the data in DSSAT format. However, WeatherMan was not designed for handling climate change scenarios.

    October 7, 2018 at 6:06 am #

    I am trying to use weather Analogue Ver. to predict the last 6 months using historical dataset and come across following error.

    ” in not valid integer value.

    Activity log
    @ Processing the Form data done.
    @ Extracting data from the Project File done.
    @ Extracting data from Neutral, Cold and Warm files done.

    @ Files are Seperate, using Algorithm Normal !
    # Start Processing Refrence File: C:\DSSAT47\Tools\WeatherAnalogue\Separate\KADO9001.WTH
    # Strat Processing History File: C:\DSSAT47\Tools\WeatherAnalogue\Separate\KADO9001.WTH
    # Dumping Predict File: C:\DSSAT47\WEATHER\GEN\KADO9001.WTG

    I have use inbuilt weather files KADO7701 – KADO8901 and placed under

    and incomplete file under

    Thanks in advance.

  9. nikita
    June 11, 2019 at 8:07 am #

    when i am generating weather file in DSSAT4.7.5.0. Error showing ” there appear to be non-numeric input in the input grid ; data is found in cell-row1 column0. 23-03-2016 is not a valid number.”
    how can i resolve this.
    Thanks in advance

  10. Gelgelo wako
    June 30, 2019 at 4:36 am #

    hi how can i download the past 30 years weather data in my location Africa Ethiopia

    • Gerrit Hoogenboom
      June 30, 2019 at 4:11 pm #

      We are unable to provide long-term weather data as this is the responsibility of the DSSAT User. However, we provide links to various weather data sources on the DSSAT portal

  11. Maria
    October 25, 2019 at 2:35 am #

    I would like to create weather scenarios for example what would happen if during my growing period it was 10% more rainfall or 10% less rainfall. I think this could be done with environment modifications but, how to do it? Should I enter the 10% of increase for every single day?

    • Gerrit Hoogenboom
      January 2, 2020 at 4:02 pm #

      In the environmental modification section you define the starting date for your weather modification. This is repeated for each day until you set it back to normal by changing the multiplier to “1.” For 10% more rainfall you set your multiplier to 1.10; for 10% less rainfall you set your multiplier to 0.9.

  12. Dereje Reta
    November 25, 2019 at 4:44 am #

    Hi!Dear DSSAT Founder,
    I have monthly solar radiation that collected from weather station of the study area.However DSSAT needs daily solar radiation.How can I convert such monthly solar radiation to daily solar radiation using weatherman of DSSAT?

    Thank you

    • Gerrit Hoogenboom
      January 2, 2020 at 3:59 pm #

      Unfortunately we do not have tools in DSSAT to convert monthly solar radiation to daily solar radiation data. If the weather station collected solar radiation data, then the original daily data should still be available.

  13. Shivani
    September 26, 2020 at 7:08 am #

    Sir, I am using DSSAT 4.7 and when I generate my daily weather files for the RCPs then it takes a very long time…. also even after that some weather files show -99 values? What could be the reason?

    • Gerrit Hoogenboom
      October 9, 2020 at 5:32 pm #


      I am not really sure what the issue is and what you are trying to do. The weather generator in DSSAT requires a climate file as input based on DSSAT standards. DSSAT does not really generate future weather data from RCPs.

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