Five usual sources, ordered by how strongly Rio Rancho's own weather and housing record points at each.
Flashing and seams
Water follows the metal around chimneys, vents, skylights and wall joints before it ever reaches a shingle. A stain that sits right under one of those points to the flashing or its sealant.
In Rio Rancho: Rio Rancho has about 101 freeze-thaw days a year, the expand-and-shrink cycle that pulls those joints apart. That is #20 of 209 cities we cover.
Hail bruises that open later
A hailstone can crack the mat under the granules without a visible hole. The roof sheds water for a while, then leaks weeks or months afterwards, often in the first hard rain of the next season.
In Rio Rancho: Hail of 1 inch or larger fell on 14 days in the county's NOAA record; the largest stone was 1.75 inches.
Lifted or missing shingles
Wind folds a shingle back and breaks its seal; the next rain goes under it. From the ground you may see a bare strip, a flapping tab, or granules and tabs in the yard after a blow.
In Rio Rancho: NOAA logged 9 days with 58 mph or stronger thunderstorm wind in the county since 2014, and a peak gust of 79 mph. That is #202 of 209 cities we cover.
An old roof wearing through
Shingles go brittle, sealant dries out and a second layer hides the real condition of the deck. When leaks appear in several rooms, the roof may be at the end of its life, not just one spot.
In Rio Rancho: 13% of homes here were built before 1980 and the median home dates from 2000. That is #204 of 209 cities we cover.
Heavy rain finding a weak spot
Exposed nail heads, a worn pipe boot or a low-slope section only fail when a lot of water arrives at once. If the leak shows only in downpours, look there first.
In Rio Rancho: 0.2 days a year bring an inch or more of rain here, out of 10.2 inches in total. That is #207 of 209 cities we cover.