Historical Weather For 2003 in Birmingham, Alabama, USA

Location

This report describes the historical weather record at the Birmingham International Airport (Birmingham, Alabama, United States) during 2003. This station has records back to January 1948.

Birmingham, Alabama has a warm humid temperate climate with hot summers and no dry season. The area within 25 mi of this station is covered by forests (82%), built-up areas (9%), and croplands (8%)

Calendar

Daylight saving time (DST) was observed at Birmingham, Alabama during 2003. There were two time changes during 2003:

  • DST started on Sunday April 6, 2003 at 3:00 am, from CST (GMT-6) to CDT (GMT-5).
  • DST ended on Sunday October 26, 2003 at 1:00 am, from CDT (GMT-5) to CST (GMT-6).

2003 was not a leap year, so it has 365 days and no February 29th. The first leap year before 2003 was 2000 and the first after was 2004.

The summer and winter solstices and the spring and fall equinoxes mark the passing of the seasons. They fall on nearly the same day each year, with differences of a day or two depending on the year. In 2003 they occurred on:

Spring Equinox Friday, 21 March 2003.
Summer Solstice Saturday, 21 June 2003.
Fall Equinox Tuesday, 23 September 2003.
Winter Solstice Monday, 22 December 2003.

Temperature

The hottest day of 2003 was August 15, with a high temperature of 92°F. For reference, on that day the average high temperature is 90°F and the high temperature exceeds 96°F only one day in ten. The hottest month of 2003 was August with an average daily high temperature of 88°F.

Relative to the average, the hottest day was February 15. The high temperature that day was 74°F, compared to the average of 58°F, a difference of 16°F. In relative terms the warmest month was November, with an average high temperature of 70°F, compared to an typical value of 65°F.

The longest warm spell was from October 29 to November 13, constituting 16 consecutive days with warmer than average high temperatures. The month of November had the largest fraction of warmer than average days with 80% days with higher than average high temperatures.

Temperature

The daily low (blue) and high (red) temperature during 2003 with the area between them shaded gray and superimposed over the corresponding averages (thick lines), and with percentile bands (inner band from 25th to 75th percentile, outer band from 10th to 90th percentile). The bar at the top of the graph is red where both the daily high and low are above average, blue where they are both below average, and white otherwise.

The coldest day of 2003 was January 24, with a low temperature of 7°F. For reference, on that day the average low temperature is 34°F and the low temperature drops below 21°F only one day in ten. The coldest month of 2003 was January with an average daily low temperature of 30°F.

Relative to the average, the coldest day was January 24. The low temperature that day was 7°F, compared to the average of 34°F, a difference of 27°F. In relative terms the coldest month was January, with an average low temperature of 30°F, compared to an typical value of 34°F.

The longest cold spell was from January 10 to January 20, constituting 11 consecutive days with cooler than average low temperatures. The month of January had the largest fraction of cooler than average days with 71% days with lower than average low temperatures.

Hourly Temperature Bands

The full year of hourly temperature reports with the days of the year on the horizontal and the hours of the day on the vertical. The hourly temperature measurement is color coded into meaningful temperature bands: frigid is purple (below 15°F), freezing is blue (15°F to 32°F), cold is dark green (32°F to 50°F), cool is light green (50°F to 65°F), comfortable is yellow (65°F to 75°F), warm is light red (75°F to 85°F), hot is medium red (85°F to 100°F), sweltering is dark red (above 100°F), and missing data is pink.

Clouds

The clearest month of 2003 was October, with 68% of days being more clear than cloudy. The longest spell of clear weather was from September 28 to October 6, constituting 9 consecutive days that were clearer than they were cloudy.

Cloud Coverage

The fraction of time spent in each of the five sky cover categories over the course of 2003 on a daily basis. From top (most blue) to bottom (most gray), the categories are clear, mostly clear, partly cloudy, mostly cloudy, and overcast. Pink indicates missing data. Outside of the United States clear skies are often reported ambiguously, leading them to be lumped in with the missing data. The bar at the top of the graph is gray if the sky was cloudy or mostly cloudy for more than half the day, blue if it is clear or mostly clear for more than half the day, and blue-gray otherwise.

The cloudiest month of 2003 was February, with 75% of days being more cloudy than clear. The longest spell of cloudy weather was from February 14 to February 23, constituting 10 consecutive days that were cloudier than they were clear.

Hourly Cloud Coverage

The full year of hourly cloud coverage reports with the days of the year on the horizontal and the hours of the day on the vertical. The sky cover is color coded: from most blue to most gray, the categories are clear, mostly clear, partly cloudy, mostly cloudy, and overcast. Pink indicates missing data. Outside of the United States clear skies are often reported ambiguously, leading them to be lumped in with the missing data.

Precipitation

This station reports both the quantity of liquid precipitation and categorical observations of precipitation (e.g., moderate rain, or heavy snow). Both are subject to erroneous reports, but the former is particularly prone to false reports, especially ones indicating an excessive quantity of precipitation. Please bear this in mind when reading the extrema reported in this section.

Liquid Equivalent Quantity

The day with the largest quantity of precipitation was August 3. That day saw 4.461" of liquid (or liquid equivalent) precipitation, compared to a median value of 0.187". The month with the most precipitation was August, with 9.083", compared to a median value of 2.937".

As determined by quantitative measurements, the longest dry spell was from October 18 to November 18, constituting 32 consecutive days with no measured precipitation. The month with the largest fraction of dry days was September, with 93% of days reporting no measured precipitation at all.

The month with the largest fraction of days with at least some measured precipitation was June, with 50% of days reporting some measured precipitation.

Precipitation Quantity

The daily measured quantity of liquid (or liquid equivalent in the case of solid precipitation) precipitation over the course of 2003, with the median non-zero quantity (thick gray line) and 10th, 25th, 75th, and 90th non-zero percentiles (shaded areas). The bar at the top of the graph is green if any precipitation was measured that day and white otherwise.

Present Weather Reports

This station reports when significant weather events (including precipitation) are visually observed at or near the station. Such events do not always correspond to measured quantities of liquid equivalent precipitation, such as when the event is near by not at the station, or in the case of solid precipitation that does not melt in the collection basin.

The day in 2003 with the most precipitation observations was July 1. There were 22 hourly weather reports that day (out of a maximum of 24) in which some form of precipitation was observated at or near the station. The month with the most precipitation observations was February, with 132 hourly present weather reports involving some form of precipitation.

Precipitation Reports

The daily number of hourly observed precipitation reports during 2003, color coded according to precipitation type, and stacked in order of severity. From the bottom up, the categories are thunderstorms (orange); heavy, moderate, and light snow (dark to light blue); heavy, moderate, and light rain (dark to light green); and drizzle (lightest green). Not all categories are necessarily present in this particular graph. The faint shaded areas indicate climate normals. The bar at the top of the graph is green if any precipitation was observed that day and white otherwise.

As determined by the present weather reports, the longest dry spell was from September 1 to September 21, constituting 21 consecutive days with no observed precipitation. The month with the largest fraction of days without observed precipitation was September, with 90% of days reporting no observed precipitation at all.

The month with the largest fraction of days with at least some observed precipitation was May, with 61% of days reporting some observed precipitation.

Hourly Weather Reports

The full year of hourly present weather reports with the days of the year on the horizontal and the hours of the day on the vertical. The color-coded categories are thunderstorms (orange); heavy, moderate, and light snow (dark to light blue); heavy, moderate, and light rain (dark to light green); drizzle (lightest green); freezing rain and sleet (light and dark cyan); snow grains (lightest blue); hail (red); fog (gray); and haze (brownish gray).

Snow

Either snow is exceptionally rare at this location or this station did not reliably report it during 2003.

Humidity

Humidity is an important factor in determining how weather conditions feel to a person experiencing them. Hot and humid days feel even hotter than hot and dry days because the high level of water content in humid air discourages the evaporation of sweat from a person's skin.

When reading the graph below, keep in mind that the hottest part of the day tends to be the least humid, so the daily low (brown) traces are more relevant for understanding daytime comfort than the daily high (blue) traces, which typically occur during the night. Applying that observation, the least humid month of 2003 was January with an average daily low humidity of 42%, and the most humid month was May with an average daily low humidity of 61%.

But it is important to keep in mind that humidity does not tell the whole picture and the dew point is often a better measure of how comfortable a person will find a given set of weather conditions. Please see the next section for continued discussion of this point.

Humidity

The daily low (brown) and high (blue) relative humidity during 2003 with the area between them shaded gray and superimposed over the corresponding averages (thick lines), and with percentile bands (inner band from 25th to 75th percentile, outer band from 10th to 90th percentile).

Dew Point

Dew point is the temperature below which water vapor will condense into liquid water. It is therefore also related to the rate of evaporation of liquid water. Since the evaporation of sweat is an important cooling mechanism for the human body, the dew point is an important measurement for understanding how dry, comfortable, or humid a given set of weather conditions will feel.

Generally speaking, dew points below 50°F will feel a bit dry to some people, but comfortable to people accustomed to dry conditions; dew points from 50°F to 68°F are fairly comfortable to most people, and dew points above 68°F are increasingly uncomfortable, becoming oppressive around 77°F.

To take some examples, and basing our categorization on the daily high dew point in 2003, January had 26 dry days, 5 comfortable days, and no humid days; April had 5 dry days, 25 comfortable days, and no humid days; July had no dry days, 1 comfortable day, and 30 humid days; and October had 4 dry days, 27 comfortable days, and no humid days.

Dew Point

The daily low (blue) and high (red) dew point during 2003 with the area between them shaded gray and superimposed over the corresponding averages (thick lines), and with percentile bands (inner band from 25th to 75th percentile, outer band from 10th to 90th percentile).

Wind

The highest sustained wind speed was 41 mph, occurring on July 21; the highest daily mean wind speed was 17 mph (February 22); and the highest wind gust speed was 55 mph (June 11).

The windiest month was January, with an average wind speed of 8 mph. The least windy month was August, with an average wind speed of 4 mph.

Wind Speed

The daily low and high wind speed (light gray area) and the maximum daily wind gust speed (tiny blue dashes).

Visibility

Visibility is the maximum distance at which a given reference object or light can be clearly discerned. In the United States, visibilities that are greater than or equal to 10 miles are typically reported as 10 miles.

The day of 2003 with the lowest average visibility was February 17, with an average visibility of 3.1 mi. The month with the lowest average visibility was August, with an average visibility of 7.8 mi. With an average visibility of 9.2 mi, the month of December had the highest average visibility.

Visibility

The daily average visibility, depicted as gray bars encroaching down from the top of the graph.

Cloud Ceiling

The cloud ceiling is the altitude of the lowest layer of clouds that are at categorized as broken (mostly cloudy) or overcast (cloudy). If no such cloud layer exists then the ceiling is unlimited and no value is reported.

The day of 2003 with the lowest average cloud ceiling was October 18, with an average cloud ceiling of 213'. The month with the lowest average cloud ceiling was December, with an average cloud ceiling of 3887'. The month of July has the highest average cloud ceiling, with an average cloud ceiling of 12311'.

Cloud Ceiling

The daily average cloud ceiling, depicted as gray bars encroaching down from the top of the graph. Missing data or days with insufficient clouds to define a cloud ceiling are shown as white columns.