+
+7. What values are valid for a --headers list?
+----------------------------------------------
+The default set it uses if you don't override it yourself on the command
+line or in configuration is as follows::
+
+ heat_index
+ precipitation_last_hour
+ relative_humidity
+ sky_conditions
+ temperature
+ weather
+ wind
+ windchill
+
+These are a case-insensitive match against the start of lines in a
+decoded METAR up to the first colon (:) with spaces optionally replaced
+by underscores (_). You can see the full METAR for a given condition
+report by passing --verbose or by observing one directly (perhaps by
+looking in your *datacache* directory). Unfortunately I haven't found
+any proper specification for the decoded METAR format used by the NWS so
+know of no comprehensive list of what lines might appear.