You can use grads software to analyse this data. Grads software is one of the best soft wares to analyse gridded data sets. This software is available on COLA's website. it's freely available software and can be installed to all types of OSs. good online help is available along with sample scripts.

Dear Sandip Sasane,

In most studies, the data of temperature and precipitation are used in grid points. There are two types of grid points; irregular and regular. The irregular grid points are usually processed the raw data observed at meteorological stations, while the regular grid points used for the data after processing, such as objective analysis, 4D assimilation, products of atmospheric models and / or re-analysis, etc. The methodology of data processing for both types of grids is same, because they always use the same method of discrete statistics for processing time series of meteorological data. Here are some links where you can find examples of the processing temperature and precipitation.

https://www.researchgate.net/publication/304102479_Analysis_of_annual_and_seasonal_temperature_trends_using_the_Mann-Kendall_test_in_Vojvodina_Serbia

https://www.researchgate.net/publication/284722652_Annual_and_seasonal_variability_of_precipitation_and_temperatures_in_Slovenia_from_1961_to_2011

https://www.researchgate.net/publication/260971431_Annual_and_seasonal_variability_of_precipitation_in_Vojvodina_Serbia

https://www.researchgate.net/publication/257449375_Aridity_in_Vojvodina_Serbia

Regards,

Milivoj B. Gavrilov

Article Analysis of annual and seasonal temperature trends using the...

Article Annual and seasonal variability of precipitation and tempera...

Article Annual and seasonal variability of precipitation in Vojvodina, Serbia

Article Aridity in Vojvodina, Serbia

Dear Sandip,

Attached I send you two works (RG links) in which the applied methods for obtaining and assessing the trend about which I wrote in the second RG message.

https://www.researchgate.net/publication/280317329_ASSESSING_AVERAGE_ANNUAL_AIR_TEMPERATURE_TRENDS_USING_THE_MANN-KENDALL_TEST_IN_KOSOVO

https://www.researchgate.net/publication/275951744_The_analysis_temperature_trends_in_Vojvodina_Serbia_from_1949_to_2006

Regards,

M.B.Gavrilov

Article Assessing average annual air temperature trends using the Ma...

Article The analysis temperature trends in Vojvodina (Serbia) from 1...

Dear Sandip Baban Sasane,

Regarding problems due to unavailability of data at tehsil level, it is not really advisable to go for  1° x 1° Gridded rainfall and temperature. That will not solve your problem. Since, 1° is nearly equal to 110 kilometers, a 1° x 1° box will have an area of above 12000 sq. km. The total area of Ahmednagar is 17413 sq. km. So you will get 1 station (or maximum 2) located within the district. So that wont help for Tehsil level. If you are getting temperature data for district as a whole, it will be not much different from 1° x 1° Gridded data. It is better to go for finer grid data. From IMD Pune, you can get 0.25° x 0.25° gridded rainfall data. The gridded data for temperature is available at 1° x 1° resolution. But you can use this temperature data, because unlike rainfall, temperature will not vary much within such a small scale (Tehsil level). So you can consider the temperature of the whole district to be uniform. For rainfall, I would suggest to get finer resolution data i.e. ground station data or 0.25° x 0.25° gridded data. (Ahmednagar receives a very little annual rainfall too.)

GrADS software is used when you have a large area and a large number of grids. GrADS is extremely helpful for clear presentation of the spatial distribution. For your case, GrADS is not  advisable (as per my opinion).

Regarding methodologies of trend analysis, Mann-Kendall, Modified Mann-Kendall and Sen slope estimators are popular ones. You can refer the following articles and cite them if they are useful to you. One article is regarding trend of rainfall for Raipur district (district as a whole) and the other one is for 39 stations over a river basin.

https://www.researchgate.net/publication/301889235_STATISTICAL_TREND_ANALYSIS_OF_MONTHLY_RAINFALL_FOR_RAIPUR_DISTRICT_CHHATTISGARH

https://www.researchgate.net/publication/300045447_Statistical_analysis_of_precipitation_over_Seonath_River_Basin_Chhattisgarh_India

I hope this helps. All the best !

Article Statistical analysis of precipitation over Seonath River Bas...

Article STATISTICAL TREND ANALYSIS OF MONTHLY RAINFALL FOR RAIPUR DI...

Dear Sandip,

In the last message I described my approach in two steps. For trend analysis (for getting trend) I used EXEL. This is a method for obtaining linear equation trend or regression equation. This equation was assessed with the Mann-Kendall test. So, I have not used the entire Mann-Kendall method, only the Mann-Kendall test. That's better, because the trend obtained independently of the test.

Regard,

M.B.Gavrilov

Dear 

There is another option available for your analysis... 

You might have know about SWAT Global Weather  Data which is available freely on web and it is in half degree interval regular gridded data (They are providing CSV Files)... the results will be more or less similar to your IMD Dataset. 

I hope that it will be helpful to your research progression.

With warm regards