Florida dairy farms are seasonal in their reproductive performance due to the hot summers. The amount of seasonality across farms has not been quantified, however. The objective was to describe the distribution of seasonality in the number of breedings (NB) and the average conception rate (CR) of dairy farms in Florida. We used reproductive data from USDA-AGIL, collected through DHIA, from the year 2010. Farms with annual NB < 100 and annual average CR > 0.75 were not used. We calculated the ratio of breedings (BR) as the NB in a calendar month divided by the average monthly NB. We also calculated the CR per calendar month for each farm. A sigmoidal function was fitted per farm to measure seasonality as is common in economic studies. The final data set had 36 (BR) and 33 (CR) farms. Goodness of fit of the sigmoidal function was measured by the mean square of errors (MSE). Measures of seasonality were the range (max – min) and minmax ratio (min/max) from the sigmoidal functions. Means and 5th, 25th, 50th, 75th and 95th percentiles are reported as well as Pearson correlations. For the BR, the mean ± SD of MSE were 0.31 ± 0.73. In the fitted model, the mean ± SD of BR were 1.21 ± 1.08. The 5 percentiles were 0.94, 0.98, 0.99, 1.04 and 1.46, respectively. The mean BR range was 1.261 and the 5 percentiles were 0.10, 0.35, 0.695, 1.32 and 2.46, respectively. The mean minmax ratio of BR was 0.45 and 5 percentiles were −0.03, 0.27, 0.49, 0.70 and 0.90. For CR, the mean ± SD of MSE were 0.01 ± 0.01. The mean ± SD of CR were 0.40 ± 0.13. The 5 percentiles were 0.26, 0.30, 0.38, 0.43 and 0.63, respectively. The mean CR range was 0.30 and 5 percentiles were 0.09, 0.21, 0.27, 0.36 and 0.71 respectively. The mean minmax ratio of CR was 0.46 and the corresponding 5 percentiles were 0.05, 0.33, 0.46, 0.58 and 0.80, respectively. Correlations between the ranges and minmax ratios were −0.96 for BR and −0.72 for CR. Maximum values were typically observed around March and minimum values around August for both BR and CR. The sigmoidal function did not necessarily describe the seasonal pattern well. In conclusion, many farms were very seasonal but different measures of seasonality may be needed.