Aggregation type 
Meaning 
avg 
The average value in the aggregation period. 
avg_ge(val) 
The number of days when the average value is greater than or equal to val. Aggregation
period must be one day or longer. The argument val is a
ValueTuple.

avg_le(val) 
The number of days when the average value is less than or equal to val. Aggregation period
must be one day or longer. The argument val is a
ValueTuple.

count 
The number of nonnull values in the aggregation period.

diff 
The difference between the last and first value in the aggregation period.

exists 
Returns True if the observation type exists in the database. 
first 
The first nonnull value in the aggregation period. 
firsttime 
The time of the first nonnull value in the aggregation period.

gustdir 
The direction of the max gust in the aggregation period.

has_data 
Returns True if the observation type
exists (either in the database or as an xtype) and has at least one
nonnull value in the aggregation period.

last 
The last nonnull value in the aggregation period. 
lasttime 
The time of the last nonnull value in the aggregation period.

max 
The maximum value in the aggregation period. 
maxmin 
The maximum daily minimum in the aggregation period. Aggregation period must be one day or longer.

maxmintime 
The time of the maximum daily minimum. 
maxsum 
The maximum daily sum in the aggregation period. Aggregation period must be one day or longer.

maxsumtime 
The time of the maximum daily sum. 
maxtime 
The time of the maximum value. 
max_ge(val) 
The number of days when the maximum value is greater than or equal to val. Aggregation
period must be one day or longer. The argument val is a
ValueTuple.

max_le(val) 
The number of days when the maximum value is less than or equal to val. Aggregation period
must be one day or longer. The argument val is a
ValueTuple.

meanmax 
The average daily maximum in the aggregation period. Aggregation period must be one day or longer.

meanmin 
The average daily minimum in the aggregation period. Aggregation period must be one day or longer.

min 
The minimum value in the aggregation period. 
minmax 
The minimum daily maximum in the aggregation period. Aggregation period must be one day or longer.

minmaxtime 
The time of the minimum daily maximum. 
minsum 
The minimum daily sum in the aggregation period. Aggregation period must be one day or longer.

minsumtime 
The time of the minimum daily sum. 
mintime 
The time of the minimum value. 
min_ge(val) 
The number of days when the minimum value is greater than or equal to val. Aggregation
period must be one day or longer. The argument val is a
ValueTuple.

min_le(val) 
The number of days when the minimum value is less than or equal to val. Aggregation period
must be one day or longer. The argument val is a
ValueTuple.

not_null 
Returns truthy if any value over the aggregation period is nonnull.

rms 
The root mean square value in the aggregation period.

sum 
The sum of values in the aggregation period. 
sum_ge(val) 
The number of days when the sum of value is greater than or equal to val. Aggregation
period must be one day or longer. The argument val is a
ValueTuple.

sum_le(val) 
The number of days when the sum of value is less than or equal to val. Aggregation period
must be one day or longer. The argument val is a
ValueTuple.

tderiv 
The time derivative between the last and first value in the aggregation period. This is the
difference in value divided by the difference in time.

vecavg 
The vector average speed in the aggregation period. 
vecdir 
The vector averaged direction during the aggregation period.
