I have a dataset (timeseries from 2010 to 2019 rainfall data from various districts near vellore).
When I ran the ADF(Augmented Dickey-Fuller Test) i got my dataset to be Stationary! meaning no seasonality!
My question is that am I doing something wrong? because normally rainfall occurs more in particular months(rainy season ofc) So shouldn't there be seasonality in my dataset?
ADF Result
Results of Dickey-Fuller Test:
Test Statistic -1.770941e+01
p-value 3.507811e-30
#Lags Used 7.000000e+00
Number of Observations Used 3.644000e+03
Critical Value (1%) -3.432146e+00
Critical Value (5%) -2.862333e+00
Critical Value (10%) -2.567192e+00
According to this result my test statistic of -17.7 is very small compared to critical values -2.56(10%) Hence this means my data is already stationary!.
Dataset contains daily data so there are a lot of 0's too, does this affect the seasonality?
Thank you!
Check the same with KPPS test with checking the seasonal Trend kpps(df,regression='ct')
The parameter regression = 'ct' will check over the seasonal trend