San Antonio Northwest C23 Data by Site by Date (all parameters)

Use this form to retrieve hourly data collected at San Antonio Northwest C23. Although this is the most current data, it is not considered official until it has been certified by the technical staff. This information is updated hourly.

This web page provides the most current hourly averaged data available. Our convention for time-tagging data is the beginning of each hour. For example, values shown for the noon hour are based on measurements taken from noon to 1:00 p.m. The noon average will not be calculated until after 1:00 p.m. The noon average will then be available on our external server from 1:15 p.m. to 1:30 p.m. This results in an apparent one-hour time lag in the data. We also present our data in Local Standard Time for each measuring site. For most of Texas this is Central Standard Time. During Daylight Savings, this introduces another apparent one-hour time lag in the data.

Use the controls below to select a different date or time format and to control cell highlighting based on measured nitrogen dioxide or PM-2.5 levels. Click on the Generate Report button once you have made your selections. Click on the Plot Data button once the tabular report has been generated to open a separate window containing data plots.

Select a different site

Month:	Day:	Year:	Time Format:

Nitrogen Dioxide Highlights: Moderate Unhealthy for Sensitives Unhealthy Very Unhealthy Hazardous

PM-2.5 Highlights: Moderate Unhealthy for Sensitives Unhealthy Very Unhealthy Hazardous

Green underline for validated data

The table below contains hourly averages for all the pollutants and meteorological conditions measured at San Antonio Northwest C23 for Monday, May 20, 2013. All times shown are in CST.

Parameter Measured	Morning												Afternoon			Parameter Measured	POC
Parameter Measured	Mid	1:00	2:00	3:00	4:00	5:00	6:00	7:00	8:00	9:00	10:00	11:00	Noon	1:00	2:00	Parameter Measured	POC
Nitric Oxide	0.2	0.2	0.1	0.3	0.1	0.2	0.2	CAL	CAL	CAL	CAL	-0.0	*-0.2*	FEW	NA	Nitric Oxide	1 ^MDL
Nitrogen Dioxide	LIM	SPZ	SPZ	LIM	LIM	LIM	CAL	CAL	CAL	CAL	CAL	LIM	LIM	LIM	NA	Nitrogen Dioxide	1 ^R ^MDL
Oxides of Nitrogen	LIM	SPZ	SPZ	LIM	LIM	LIM	CAL	CAL	CAL	CAL	CAL	NEG	NEG	FEW	NA	Oxides of Nitrogen	1 ^MDL
Ozone	23	24	27	28	28	26	23	24	29	36	44	49	53	FEW	NA	Ozone	2 ^R ^MDL
Wind Speed	8.3	7.5	8.4	8.9	8.5	*7.4*	7.5	8.2	8.7	9.0	10.3	10.9	11.0	FEW	NA	Wind Speed	1
Resultant Wind Speed	8.0	7.3	8.2	8.6	8.2	*7.1*	7.1	7.7	8.2	8.3	9.5	10.3	10.2	FEW	NA	Resultant Wind Speed	1
Resultant Wind Direction	133	*126*	127	127	131	133	138	141	141	144	149	132	139	FEW	NA	Resultant Wind Direction	1
Maximum Wind Gust	17.0	15.5	16.3	17.5	17.2	15.6	*13.8*	16.2	15.7	17.8	20.5	21.9	23.1	FEW	NA	Maximum Wind Gust	1
Std. Dev. Wind Direction	16	14	13	15	16	17	18	19	20	22	22	19	21	FEW	NA	Std. Dev. Wind Direction	1
Outdoor Temperature	75.0	74.2	74.3	74.1	*74.1*	74.2	74.5	75.6	77.4	80.3	83.8	86.7	89.0	FEW	NA	Outdoor Temperature	1
PM-2.5 (Local Conditions) Acceptable	*10.97*	11.23	11.23	13.27	13.30	16.00	13.69	14.95	16.87	17.96	22.21	26.19	31.39	FEW	NA	PM-2.5 (Local Conditions) Acceptable	3 ^MDL
Parameter Measured	Mid	1:00	2:00	3:00	4:00	5:00	6:00	7:00	8:00	9:00	10:00	11:00	Noon	1:00	2:00	Parameter Measured	POC
Parameter Measured	Morning												Afternoon			Parameter Measured	POC
	Maximum values for each parameter are bold within the table. Minimum values are *bold italic*.
	^R - Data from this instrument meets EPA quality assurance criteria for regulatory purposes.

PLEASE NOTE: This data has not been verified by the TCEQ and may change. This is the most current data, but it is not official until it has been certified by our technical staff. Data is collected from TCEQ ambient monitoring sites and may include data collected by other outside agencies. This data is updated hourly. All times shown are in local standard time unless otherwise indicated.

Following EPA reporting guidelines, negative values may be displayed in our hourly criteria air quality data beginning 1/1/2013, down to the negative of the EPA listed Method Detection Limit (MDL) for the particular instrument that made the measurements. The reported concentrations can be negative due to zero drift in the electronic instrument output, data logger channel, or calibration adjustments to the data. Prior to 1/1/2013, slightly negative values were automatically set to zero.