Texas Groundwater Temperatures
Average Groundwater Temperatures for the Cities in Texas
Temperature is important to consider when dealing with hard water because calcium dissolves more easily in cold water. Most substances that dissolve in water, such as sugar, do not behave in this manner. It is common knowledge that you can dissolve more sugar in hot water than cold. Calcium has the opposite effect: the hotter the water, the less calcium it can dissolve. If your water source is deep in the earth (higher pressure also contributes to increased calcium solubility) and the groundwater is very cold, you can almost certainly expect hard water. Groundwater is so hard in some areas that water utilities must blend it with surface water to reduce the hardness. If you would like more information on the hard water levels in your area please see our hard water map.
Another important reason to know your average groundwater temperatures is if you are trying to determine which tankless water heater to purchase. The reason for this is because in colder climates the groundwater starting temperature is colder than in warmer climates. This causes the tankless water heater to work harder to increase the water temperature in colder climates, which in turn causes the flow rate to decrease in parallel. For example, if the starting water temperature is 52°F and you need to raise the water temperature to 110°F. Then your tankless water heater must be able to raise the temperature of the water by 58°F while still providing adequate flow to support the fixtures you wish to run at the same time.
How Flow Rates are Affected by Temperature
In the example below, you can see the impact that temperature has on flow rates. This example is based on a tankless water heater that has a flow rate rated for 8 GPM.
| Temperature Zone | Efficiency |
|---|---|
| +71 °F | 100% (8 GPM) |
| 61 – 70 °F | 73% (5.8 GPM) |
| 51 – 60 °F | 58% (4.6 GPM) |
| 41 – 50 °F | 48% (3.8 GPM) |
| < 40 °F | 41% (3.2 GPM) |
Based on the corresponding flow rates for each appliance that are listed. A tankless water heater that is rated with a flow rate of 8 GPM (gallons per minute) is capable of running these items at the same time in regions with an average groundwater
temperature of 72°F.
Shower = 3 GPM
Kitchen Sink = 1.5 GPM
Washing Machine = 2.5 GPM
Total = 7 GPM
If you take this same exact tankless water heater and install it in a region that has an average groundwater temperature of 52°F (green zone). This will lower that tankless water heater's max GPM output to 4.64 GPM.
Shower = 3 GPM
Kitchen Sink = 1.5 GPM
Total = 4.5 GPM
As you can see before purchasing a tankless water heater it's important to know the impact temperature has on its ability to heat water and its effect on the total GPM needs of your household.
Texas Groundwater Temperature Yearly Average
| City and zip codes | Groundwater Temperatures |
|---|---|
Amarillo 79101 | 79102 | 79103 | 79104 | 79105 | 79106 | 79107 | 79108 | 79109 | 79110 | 79111 | 79118 | 79119 | 79121 | 79124 | 58°F |
Abilene 79601 | 79602 | 79603 | 79605 | 79606 | 79699 | 64°F |
Allen 75002 | 75013 | 62°F |
Arlington 76001 | 76002 | 76006 | 76010 | 76011 | 76012 | 76013 | 76014 | 76015 | 76016 | 76017 | 76018 | 79119 | 79121 | 79124 | 62°F |
Austin 78703 | 78704 | 78705 | 78712 | 78717 | 78719 | 78721 | 78722 | 78723 | 78724 | 78725 | 78726 | 78727 | 78728 | 78729 | 78730 | 78731 | 78732 | 78733 | 78734 | 78735 | 78736 | 78737 | 78738 | 78739 | 78739 | 78741 | 78742 | 78744 | 78745 | 78746 | 78747 | 78748 | 78749 | 78750 | 78751 | 78752 | 78753 | 78754 | 78756 | 78757 | 78758 | 78759 | 61°F |
Beaumont 77701 | 77702 | 77703 | 77705 | 77706 | 77707 | 77708 | 77713 | 68°F |
Bedford 76021 | 76022 | 60°F |
Brownsville 78520 | 78521 | 78526 | 76801 | 62°F |
Bryan 77801 | 77802 | 77803 | 77807 | 77808 | 63°F |
Burelson 76028 | 62°F |
Cedar Park 78613 | 64°F |
College Station 77840 | 77845 | 62°F |
Conroe 77301 | 77302 | 77303 | 77304 | 77306 | 77384 | 77385 | 59°F |
Corpus Christi 78401 | 78402 | 78404 | 78405 | 78406 | 78407 | 78408 | 78409 | 78410 | 78411 | 78412 | 78413 | 78414 | 78415 | 78416 | 78417 | 78418 | 78419 | 64°F |
Euless 76039 | 76040 | 62°F |
Dallas/Fort Worth Metroplex 75201 | 75202 | 75203 | 75204 | 75205 | 75206 | 75207 | 75208 | 75209 | 75210 | 75211 | 75212 | 75214 | 75215 | 75216 | 75217 | 75218 | 75219 | 75220 | 75223 | 75224 | 75225 | 75226 | 75227 | 75228 | 75229 | 75230 | 75231 | 75232 | 75233 | 75234 | 75235 | 75236 | 75237 | 75238 | 75240 | 75241 | 75243 | 75244 | 75246 | 75247 | 75248 | 75249 | 75251 | 75252 | 75253 | 75254 | 75270 | 75287 | 75390 | 76102 | 76103 | 76104 | 76105 | 76106 | 76107 | 76108 | 76109 | 76110 | 76111 | 76112 | 76114 | 76115 | 76116 | 76118 | 76119 | 76120 | 76123 | 76126 | 76129 | 76131 | 76132 | 76133 | 76134 | 76135 | 76137 | 76140 | 76148 | 76155 | 76164 | 76177 | 76179 | 64°F |
Frisco 75034 | 75035 | 61°F |
Galveston 77550 | 77551 | 77554 | 62°F |
Garland 75040 | 75041 | 75042 | 75043 | 75044 | 62°F |
Grand Prarie 75050 | 75051 | 75052 | 75054 | 64°F |
Grapevine 76051 | 62°F |
Greater Houston 77002 | 77003 | 77004 | 77005 | 77006 | 77007 | 77008 | 77009 | 77010 | 77011 | 77012 | 77013 | 77014 | 77015 | 77016 | 77017 | 77018 | 77019 | 77020 | 77021 | 77022 | 77023 | 77024 | 77025 | 77026 | 77027 | 77028 | 77029 | 77030 | 77031 | 77032 | 77033 | 77034 | 77035 | 77036 | 77037 | 77038 | 77039 | 77040 | 77041 | 77042 | 77043 | 77044 | 77045 | 77046 | 77047 | 77048 | 77049 | 77050 | 77051 | 77053 | 77054 | 77055 | 77056 | 77057 | 77058 | 77059 | 77060 | 77061 | 77062 | 77063 | 77064 | 77065 | 77066 | 77067 | 77068 | 77069 | 77070 | 77071 | 77072 | 77073 | 77074 | 77075 | 77076 | 77077 | 77078 | 77079 | 77080 | 77081 | 77082 | 77083 | 77084 | 77085 | 77086 | 77087 | 77088 | 77089 | 77090 | 77091 | 77092 | 77093 | 77094 | 77095 | 77096 | 77098 | 77099 | 77201 | 66°F |
Irving 75038 | 75039 | 75060 | 75061 | 75062 | 75063 | 63°F |
Keller 76244 | 61°F |
Killeen 76541 | 76542 | 76543 | 76549 | 63°F |
El Paso 79901 | 79902 | 79903 | 79904 | 79905 | 79906 | 79907 | 79908 | 79911 | 79912 | 79915 | 79920 | 79922 | 79924 | 79925 | 79927 | 79928 | 79930 | 79932 | 79934 | 79935 | 79936 | 79938 | 79942 | 65°F |
Leander 78641 | 78645 | 63°F |
Lewisville 75057 | 75067 | 75077 | 66°F |
Little Elm 75068 | 62°F |
Longview 75601 | 75602 | 75603 | 75604 | 75605 | 64°F |
Laredo 78040 | 78041 | 78043 | 78044 | 78045 | 78046 | 66°F |
Lubbock 79401 | 79403 | 79404 | 79406 | 79407 | 79410 | 79411 | 79412 | 79413 | 79414 | 79415 | 79416 | 79423 | 79424 | 64°F |
Mansfield 76063 | 64°F |
Mesquite 75149 | 75150 | 67°F |
McAllen 78501 | 78503 | 78504 | 69°F |
Midland 79701 | 79703 | 79705 | 79706 | 79707 | 68°F |
New Baunfels 78130 | 78132 | 63°F |
North Richland Hills 76180 | 76182 | 62°F |
Odessa 79761 | 79762 | 79763 | 79764 | 79765 | 79766 | 68°F |
Pflugerville 78660 | 62°F |
Plano 75023 | 75024 | 75025 | 75074 | 75075 | 75093 | 75094 | 67°F |
Richardson 75080 | 75081 | 75082 | 64°F |
Round Rock 78664 | 78665 | 78681 | 66°F |
Rowlett 75088 | 75089 | 63°F |
Rusk 75785 | 65°F |
San Angelo 76901 | 76903 | 76904 | 76905 | 66°F |
San Marcos 78666 | 62°F |
San Antonio 78201 | 78202 | 78203 | 78204 | 78205 | 78207 | 78208 | 78209 | 78210 | 78211 | 78212 | 78213 | 78214 | 78215 | 78216 | 78217 | 78218 | 78219 | 78220 | 78221 | 78222 | 78223 | 78224 | 78225 | 78226 | 78227 | 78228 | 78229 | 78230 | 78231 | 78232 | 78233 | 78235 | 78237 | 78238 | 78239 | 78240 | 78242 | 78243 | 78244 | 78245 | 78247 | 78248 | 78249 | 78250 | 78251 | 78252 | 78253 | 78254 | 78255 | 78256 | 78257 | 78258 | 78259 | 78260 | 78261 | 78263 | 78264 | 78266 | 77062 | 77063 | 77064 | 77065 | 77066 | 77067 | 77068 | 77069 | 77070 | 77071 | 77072 | 77073 | 77074 | 77075 | 77076 | 77077 | 77078 | 77079 | 77080 | 77081 | 77082 | 77083 | 77084 | 77085 | 77086 | 77087 | 77088 | 77089 | 77090 | 77091 | 77092 | 77093 | 77094 | 77095 | 77096 | 77098 | 77099 | 77201 | 68°F |
Sugar Land 77478 | 77479 | 77498 | 64°F |
Temple 76501 | 76502 | 76504 | 76508 | 64°F |
Texas City 77590 | 77591 | 66°F |
Tyler 75701 | 75702 | 75703 | 75704 | 75705 | 75706 | 75707 | 75708 | 75709 | 65°F |
Victoria 77901 | 77904 | 77905 | 69°F |
Waco 76701 | 76704 | 76705 | 76706 | 76707 | 76708 | 76710 | 76711 | 76798 | 69°F |
Willis 77318 | 77378 | 68°F |
Whitchita Falls 76301 | 76302 | 76305 | 76306 | 76308 | 76309 | 76310 | 61°F |
Wylie 75098 | 68°F |
What Tankless Water Heater should You buy if you live in Texas?
Since Texas's average groundwater temperature range is between 59°F and 71°F. It is recommended that you select an orange zone or red zone tankless water heater. To see the recommended tankless water heaters that apply to the orange and red zone temperatures please follow the link that corresponds to the region of your average groundwater temperature.
| Temperature zone | Recommended Tankless Water Heater |
|---|---|
| < 40 °F | Tankless Water Heater Recommendations |
| 41 – 50 °F | Tankless Water Heater Recommendations |
| 51 – 60 °F | Tankless Water Heater Recommendations |
| 61 – 70 °F | Tankless Water Heater Recommendations |
| +71 °F | Tankless Water Heater Recommendations |
