If your rain gauge has sprung a leak, you can remove and replace the end cap. To do this, take a sturdy broomstick and slide the rain gauge flute over the end. Firmly—ok, really firmly...maybe even authoritatively—push the gauge down onto the broomstick until the cap comes off.

To replace the cap, snip the end off the glue packet. Run a thick bead of silicone around the edge of the cap, extending glue up the sides. Make sure you leave no gaps in the bead. Press the flute onto the cap and press down firmly. Leave the gauge sitting upright (don't turn it upside down, even though it will seem more stable—the glue needs air to dry) and wait 24 hours before replacing the rain gauge measurement tube.