A Century of Ocean Warming on Florida Keys Coral Reefs: Historic In Situ Observations

Table 2 Hen and Chickens Reef underwater (≈4-m depth) temperature, 1975 to 2007. Results are reported for the linear regression of monthly means vs. time (years). The plus symbol indicates a statistically significant warming trend, and the P-value is the probability that the trend could be due to chance alone. P-values at or less than 5 % are in italic. The equal symbol indicates that there was not a significant trend detected

Month	N (years)	Trend	P-value	Slope (°C year⁻¹)	Estimated warming (°C)
Jan	23	+	0.05	0.055	1.8
Feb	22	+	0.04	0.067	2.1
Mar	22	+	0.05	0.043	1.4
Apr	20	=	0.31	0.022	0.7
May	20	=	0.15	0.027	0.9
Jun	19	+	0.02	0.041	1.3
Jul	21	=	0.18	0.018	0.6
Aug	22	+	0.003	0.039	1.2
Sep	21	=	0.16	0.018	0.6
Oct	20	=	0.57	0.010	0.3
Nov	21	=	0.81	−0.004	−0.1
Dec	22	=	0.60	0.011	0.4