Climate
Tracking Climate in Louisiana
The Louisiana Department of Health (LDH) Health Data Explorer currently displays the following topics related to climate for query and download:
To explore health and environmental climate data, click here.
- Health
- Emergency Department visits, hospitalizations and deaths with a primary diagnosis of Heat Stress, also known as heat-related illness (HRI)
- Drought and Excessive Rainfall
- Monthly Palmer Drought Severity Index (PDSI) by climate division
- Heat | Temperature
- Number of days with Min Temp 80°F degrees or higher
- Number of days with Max Temp 95°F degrees or higher
- Wildfire
- Total acres and total number of suppressed wildfires by parish and state, by year
- State-level data, by year
Heat stress, also known as heat-related illness, is a preventable illness that occurs when heat exposure exceeds the physiologic capacity to cool and the core body temperature rises. When this happens, a range of heat-related symptoms and conditions may develop.
Heat stress illnesses include, but are not limited to, heat stroke, heat exhaustion, heat cramps, heat syncope, or heat rash. Anyone, regardless of age, sex, or health status may be at risk for heat stress illness especially workers who are exposed to extreme heat or work in hot environments.
Data Sources
LDH Bureau of Health Informatics
LDH State Registrar and Vital Records
Drought and Excessive Rainfall
The Palmer Drought Severity Index (PDSI) applies temperature and precipitation data to estimate the relative dryness of a region. Its scale ranges from -10 (very dry) to +10 (very wet) with 0 being normal. According to the National Center for Atmospheric Research (NCAR), The Palmer Drought Severity Index (PDSI) “uses temperature data and a physical water balance model” to “capture the basic effect of global warming on drought through changes in potential evapotranspiration.”
The National Weather Service (NWS) Climate Prediction Center offers more context to these PSDI values of drought and excessive rainfall stating that the PDSI is an important climatological tool for evaluating the scope, severity, and frequency of prolonged periods of abnormally dry or wet weather.
| -4.0 or less (Extreme Drought) | +2.0 or +2.9 (Unusual Moist Spell) |
| -3.0 or 3-.9 (Severe Drought) | +3.0 or +3.9 (Very Moist Spell) |
| -2.0 oe -2.9 (Moderate Moist Spell) | +4.0 or above (Extremely Moist) |
| -1.9 to 1.9 (Near Normal) |
Drought
A value for moderate drought begins at -2 while conditions of severe drought start at -3 and extreme drought at -4.
Excessive Rainfall
Values above +2 are considered an ‘unusual moist spell,’ with +3 a very moist spell and +4 an extremely moist spell.
Data Sources
Monthly PDSI by climate region was obtained from NOAA’s National Climatic Data Center (NCDC).
To conceptualize heat and temperature, nine weather stations were selected to represent each of Louisiana’s Climate Divisions. Stations were selected based on their high accuracy and availability of historical data. To capture the most relevant data as trends, the months May – September are displayed to determine average summer temperatures. Using the daily temperature data, the number of days with a minimum temperature over 80°F or a maximum temperature over 95°F were calculated and summed by month or year.
Nighttime temperatures that do not fall below 80°F (27°C) hamper the body’s ability to recover from high temperatures and any physical exertion throughout the day. During extended periods of summer heat, a sequence of days where nightly temperatures (daily low) do not fall below 75°F-80°F introduce higher risk of heat stress emergency department visits and hospitalizations. A sequence of days over a daily high temperature of 95°F (35°C) and a heat index of 100°F (~38°C ) have been shown to be an even better indicator of expected health impacts from heat (Louisiana Morbidity Report (2019). “Heat-Stress Illness and Mortality in Louisiana.”
Data Sources
Daily temperature data for nine different weather stations were obtained from the Southern Regional Climate Center’s Climate Information Data Portal (SRCC CLIMDAT).
Additional Info
**Please note: 3/9/2023: Some Tracking data for temperature (annual and monthly Maximum Temperature and Heat Index) is temporarily unavailable on LA’s Health Data Explorer.
To access heat: temperature data, please visit the CDC Tracking Data Explorer at: https://ephtracking.cdc.gov/DataExplorer/.
Select STEP 1: Content Area: Heat & Heat-related Illness (HRI), Select a Measure
Select STEP 2: Geography Type
Wildfire smoke is produced from burning organic matter, including trees and grass. It is composed of particulate matter, organic material (e.g. carbon dioxide, carbon monoxide, water vapor, and hydrocarbons), nitrogen oxides, and trace materials. These particulates and gases contribute to pollution in the environment and health impacts which range from eye and respiratory tract irritation to reduced lung function, bronchitis, and in some cases, smoke inhalation and death. Carbon monoxide concentrations related to wildfire smoke may pose significant harm to sensitive individuals and firefighters near the fire line. Groups more vulnerable to the effects of wildfire smoke include individuals with asthma and other chronic respiratory conditions, individuals with cardiovascular disease, older persons, children, pregnant women, and persons with reduced lung function due to smoking or Chronic Obstructive Pulmonary Disease (COPD).
Although wildfires occur naturally, scientists have indicated that climate has the potential to increase the frequency, extent, and severity of fires through increased temperatures and drought conditions. Additionally, wildfires themselves become a contributor to climate.
Overall, the amount of land area that is burned due to wildfires varies throughout the United States, with fires burning more land in the West. Western states have larger fires due to a combination of factors such as physical landscape (e.g., forest cover types), forest development/ management and mountain or desert winds (or coastal currents), which can create drier conditions (Hoover, K and Hanson, L (2019). Wildfire statistics (CRS Report No. IF10244) Retrieved from Congressional Research Service website.
Data Sources
Data were obtained from the Louisiana Department of Agriculture and Forestry (LDAF) for total fires and acres of suppressed fires in each parish.