PostGIS ST_Contains query returns null

Question

I have a shapefile of all US States that I've imported into a table with a multipolygon geometry column. (SRID 4326)

I perform a spatial query based on lat/lon to return the state abbreviation. This normally works just fine. Today a query came in for Hawaii and the query returned nothing. So naturally I opened the table up in QGIS and queried the point's coordinates. Sure enough it returned the correct result. I clicked identify and it most certainly had the correct attributes.

The query I'm using is:

SELECT states.state_abbr FROM states WHERE st_contains(states.geom, ST_SetSRID(ST_MakePoint(-159.717,21.933), 4326)) 

Does anything look wrong with that query? I tried st_intersects as well.

Answer 1

Sounds like the point just isn't in the polygon.

WITH pt AS ( SELECT ST_SetSRID(ST_MakePoint(-159.717,21.933), 4326) AS geom )
SELECT ST_Distance(states.geom, pt.geom) FROM states, pt 
WHERE states.abbr = 'HI';

And Google seems to think so too. It's close, but it's not in.

https://maps.google.ca/maps?client=safari&oe=UTF-8&q=21.933N+159.717W