diff --git a/geomagio/processing/magproc.py b/geomagio/processing/magproc.py
index 14f2fc744950131ffdf61717fc55a18fe4ac87b2..428d9288a7d851d47eabb4ff52cd987303738c4f 100644
--- a/geomagio/processing/magproc.py
+++ b/geomagio/processing/magproc.py
@@ -146,7 +146,7 @@ def write_temperature_data(
         endtime=endtime,
         timeseries=timeseries_temperature,
         observatory=observatory,
-        interval="hourly",
+        interval="hour",
         channels=["UK1", "UK2", "UK3", "UK4"],
         template=template,
         temperatures=True,