The temperature density relationship of hydrocarbons is defined in the Manual Of Petroleum Measurement Standards.
Originally this was a selection of tables created using hydrometers but these days the standard is not the tables but the calculation.
Hydrocarbons are divided into commodity groups and each group has a defined range of densities and a defined set of constants for the calculation.
Hence aviation fuels form one commodity group, lubricants another and so on.
As has been mentioned, the aviation fuels are blends.
Blending will be designed to deliver a fuel that satisfies a number of target properties which each have a reasonable set of limits. There are limits on density but these are go/no-go limits and hence have quite a wide range (as can be seen from the commodity group itself.) which usually means that all the products in a commodity group have density ranges that overlap to some degree or another.
The refiners run optimisation programs to maximise the profitable conversion of crude which means they will bias the production of the products within the allowable limits to enable them to suit the current crude slate and production call.
It is not unusual to find that certain properties will vary significantly one batch to another even sequential batches from a single refinery.
So, for any batch of aviation fuel you do need to know the density for that specific batch of fuel. This is usually reported by the refiner at 15degC.or can be measured on site.
However, because the temperature can vary in storage or as it is delivered it helps to know the density at the flowing temperature and apply volume correction factors.
There is a spreadsheet at Cheresources that performs all these calculations including volume correction factors. There are variants of this available from RMI (an email address is in the spreadsheet) if required.
Density to Temperature Correlations for Hydrocarbons - Cheresources.com Community