The chance that the index and the farm disagree. The worst case for a farmer is a drought on the farm in a year the index doesn't pay. The worst case for an insurer is paying in a year the farm was fine.

Cooperatives, micro-insurers, NGOs and farmer groups deciding whether a district rainfall index is fair to the members it covers. Run it for a few villages across the district to see where the index works and where it doesn't.

That is the finest CHIRPS gives. It mixes satellite readings with rain gauges and has records back to 1981, long enough to judge rare droughts. A single rain gauge at the farm would be better still, if you have one with a long record.

Can I use the answer in a report?

Yes, in reports, funding bids, meetings and on notice boards. Keep the line "Generated at TechnicalGIS.com" and the data credits. Each answer has its own link and is kept for 90 days.

Would a rainfall index have paid out when this farm had a drought?

Rainfall insurance usually pays on rain averaged over a district, not on what fell at each farm. Choose the district, a farm or village in it and the insured season. We go back through every season since 1991 and show how often the index and the farm agreed about the bad years, the droughts it would have missed and the payouts in good years.

1. Choose your district

Country

2. The farm or village to check Name (optional)

Coordinates

It must be inside the district. Latitude first, as in 3.1194, 35.5973. Copy it from Google Maps or OpenStreetMap, use your phone's location, or tap the map.

3. The insured season

Starts in Lasts

The index pays out in

Choose a country and a district first.

Usually ready in under a minute. Free, up to 15 new questions a day each; answers we've already worked out are instant and don't count. Privacy.

Choose a country to see its districts, then tap the map to mark the place.

District boundaries from geoBoundaries, simplified for the web.

See all the community tools, or Farm check for one farm.

How it works

Two rainfall records. We take CHIRPS satellite rainfall for the insured months in every year since 1991, once averaged over the district and once for the 5 km square holding the farm or village.
Bad years. The index "pays" in its driest years: one in three, four, five or ten, as you choose. The farm "has a drought" in its own driest years at the same rate.
The match. We list the droughts the index caught, the ones it missed and the years it paid when the farm was fine, and give the correlation between the two records (1 is a perfect match).

This checks rainfall only. A real policy may use a different data source, a different payout scale or crop yields, and farm losses from pests, disease or prices are a separate matter.

You get a short answer with the big numbers, a one-page sheet to print, a text message you can copy or send on WhatsApp, and the figures as a spreadsheet (CSV).

Official sources

We check the satellite record. For warnings and advice, go to the people whose job it is:

Global Index Insurance Facility (World Bank) : guidance on designing index insurance and reducing basis risk.
IRI, Columbia University : research and tools on index insurance and climate risk.

Data and credits

Licences checked on each provider's own page, last on 29 October 2026.

Source	Licence	Credit
CHIRPS v3 rainfall	CC BY 4.0	UCSB Climate Hazards Center CHIRPS version 3.0, processed by dynamical.org. Funk, C. et al. (2026), Sci Data 13, 718. https://doi.org/10.15780/G2JQ0P. CC BY 4.0.
geoBoundaries administrative boundaries	Per country (CC BY, ODbL or open government licence)	Runfola, D. et al. (2020) geoBoundaries: A global database of political administrative boundaries. PLoS ONE 15(4): e0231866.

Questions

What is basis risk?: The chance that the index and the farm disagree. The worst case for a farmer is a drought on the farm in a year the index doesn't pay. The worst case for an insurer is paying in a year the farm was fine.
Who is this for?: Cooperatives, micro-insurers, NGOs and farmer groups deciding whether a district rainfall index is fair to the members it covers. Run it for a few villages across the district to see where the index works and where it doesn't.
Why 5 km squares?: That is the finest CHIRPS gives. It mixes satellite readings with rain gauges and has records back to 1981, long enough to judge rare droughts. A single rain gauge at the farm would be better still, if you have one with a long record.
Can I use the answer in a report?: Yes, in reports, funding bids, meetings and on notice boards. Keep the line "Generated at TechnicalGIS.com" and the data credits. Each answer has its own link and is kept for 90 days.

See real answers for real places, all the community tools or read what we're for. Need it for a whole region or every month? Talk to us.