4  Environmental

The following includes variables that establish the estuarine setting: rainfall, light intensity, water temperature, and salinity. These variables are driven primarily by climatic patterns and largely influence water quality, biological processes, and habitat condition.

Low precipitation levels in November and December led to drought conditions at the end of 2025 and into 2026. NOAA and NIDIS report these events on their website and here for local St. Augustine drought conditions.

4.1 Data

4.1.1 Rainfall

(a) Quarterly total precipitation for 2026.
(b) Monthly total precipitation for 2026.
(c) Daily rainfall totals for days with greater than 1mm per day.
(d) Hourly rainfall intensity counts by category per month.
Figure 4.1: Rainfall at the Pellicer Creek weather station. See Maintenance Notes (8.2.2) for details on missing data.
Table 4.1: Top five highest monthly rainfall totals.
Month Year Total Precipitation (mm)
May 2009 451.0
Sep 2024 427.1
Sep 2022 399.3
Sep 2017 394.4
Sep 2004 339.9
(a) Total precipitation for April 2002-2026.
(b) Monthly total precipitation 2002-2026.
(c) Annual precipitation totals Jan 2002-June 2026.
Figure 4.2: Rainfall at the Pellicer Creek weather station.

4.1.2 Light Intensity

The plot below is interactive. Clicking on elements in the legend (months) will select or deselect months of interest. Additionally, the axis can be adjusted by selecting portions of the plot to isolate.

Figure 4.3: Total light intensity by time of day for each month based on photosynthetically active radiation (PAR) data collected at the Pellicer Creek weather station.

4.1.3 Temperature

Air and water temperatures are presented as daily averages (blue line) with historic ranges (daily range and average daily range) provided in shades of gray.

Figure 4.4: Historical daily range of air temperature at the SWMP weather station with current year daily average overlaid in blue.
(a) Pine Island
(b) San Sebastian
(c) Fort Matanzas
(d) Pellicer Creek
Figure 4.5: Historical daily range of water temperature at each SWMP water quality station with current year daily average overlaid in blue.

4.1.4 Salinity

(a) Pine Island
(b) San Sebastian
(c) Fort Matanzas
(d) Pellicer Creek
Figure 4.6: Historical daily range of salinity at each SWMP water quality station with current year daily average overlaid in blue.