  We compare the gamma-ray photon flux variability of northern blazars in the
Fermi/LAT First Source Catalog with 37 GHz radio flux density curves from the
Metsahovi quasar monitoring program. We find that the relationship between
simultaneous millimeter (mm) flux density and gamma-ray photon flux is
different for different types of blazars. The flux relation between the two
bands is positively correlated for quasars and does no exist for BLLacs.
Furthermore, we find that the levels of gamma-ray emission in high states
depend on the phase of the high frequency radio flare, with the brightest
gamma-ray events coinciding with the initial stages of a mm flare. The mean
observed delay from the beginning of a mm flare to the peak of the gamma-ray
emission is about 70 days, which places the average location of the gamma-ray
production at or downstream of the radio core. We discuss alternative scenarios
for the production of gamma-rays at distances of parsecs along the length of
the jet
