Counting cells in Excel using multiple criteria, include date ranges

I have a spreadsheet that tracks numbers of participants in a program in each California county each month, over a 1 year period, arranged by date. I need to count how many would be from each county each month. For example, in a 12-month period, there may be 50,000 participants. An annual count of 1200 might be from one county, and of those 1200, 110 might be in January, 85 in February, etc. A different county might have only 65 for the year, with 4 one month, 6 another month. I need to break out the counts, by month, by county. I can send the spreadsheet in order to give a visual.