And what they mean to us.
As has been mentioned elsewhere on this site, the Black Hills has micro-climates. To know what plants would work well, we need a pretty good idea what our elevation is. It doesn’t tell us everything we need to know about our property but it is a god start, and it’s a great ice breaker at social gatherings… you know… if you don’t have dogs.
There are several free apps that use your phone’s built-in GPS and other sensors to tell you your current altitude or elevation.
Recommended Free Altimeter Apps
Here are some popular and reliable free options for both iPhone and Android:
- My Altitude / My Elevation: These are popular, simple apps available on both major app stores. They use a combination of GPS data, network services, and your device’s internal barometer (if your phone has one) to provide an accurate reading. They work both online and offline.
- Altimeter GPS: Another good option for both platforms, designed for outdoor activities like hiking. It can track your route and record data like maximum and average elevation.
- Travel Altimeter & Elevation: A simple, uncluttered interface that provides altitude, latitude, and longitude. It can work even in areas with limited cell service once a GPS connection is established.
Built-In Phone Features
You may not even need a separate app. Your phone might already have the information available:
- iPhone: Open the default Compass app. Your current altitude is often displayed at the bottom of the screen.
- Android: Open Google Earth or sometimes Google Maps. Navigate to your location, and the altitude is typically shown at the bottom of the screen.
How They Work
These apps typically combine data from multiple sources for accuracy:
- GPS (Global Positioning System): Provides a 3D position (latitude, longitude, and altitude).
- Barometer: Newer phones have a built-in sensor that measures air pressure, which changes predictably with altitude. Apps use this for highly accurate readings.
- Network Services: Uses known location data from cell towers and Wi-Fi networks to help refine the location and cross-reference elevation data from topographical maps.
What elevation do you consider ‘the foothills’?
In the context of the Black Hills region of South Dakota, “the foothills” generally refers to the transition zone between the high elevations of the central hills and the lower, flatter prairie lands to the east and west.
The elevation range for the foothills is typically between 3,200 feet and 4,500 feet above sea level.
Here is a breakdown of how this defines the area:
- Below 3,200 ft: Considered the surrounding Great Plains or prairie land (e.g., Belle Fourche, Edgemont).
- 3,200 ft to 4,500 ft: The Foothills (e.g., Rapid City, Hermosa, Sturgis, Blackhawk, Piedmont, Spearfish). This is where many of the communities in the region are concentrated.
- Above 4,500 ft: The High Elevations or “In the Hills” (e.g., Lead, Custer, Hill City, Deadwood).
This elevation range is why you experience the specific microclimates we’ve discussed (Zone 4b to 5a) compared to the tougher Zone 3b/4a conditions found in the higher elevations.
For an example of this affects us- the elevation of the Black Hills Gardens is 4060 feet. That’s according to my iPhone app. We are about 10 miles from the town of Hermosa, which has an elevation of 3,326.
That is a perfect example of how dramatically the Black Hills topography creates unique microclimates within just a few miles!
According to Google AI, which I asked to explain this to me, the 700+ foot difference in elevation between your property (4,060 ft) and the town of Hermosa (3,326 ft) is the primary reason for those significant climate changes you observe.
Here is how that elevation difference specifically accounts for those variations:
The 700-Foot Difference SHOULD result in these characteristics:
| Feature | Your Property (4,060 ft) | Hermosa Town (3,326 ft) |
|---|---|---|
| USDA Zone | Zone 4b | Zone 4b/5a (slightly milder) |
| Winter Temps | Colder minimums, more extreme cold snaps | Milder minimums, slightly less frost risk |
| Precipitation | Likely slightly more annual precip/snow | Slightly less annual total, but similar pattern |
| Growing Season | Shorter (Avg. 120-130 days) | Longer (Avg. 130-140 days) |
| Wind/Exposure | More wind exposure, more “in the hills” feel | Often more sheltered near the town center |
Why the Climate Varies So Much
1. Cold Air Drainage (The Main Factor):
Cold air is heavier than warm air. It flows downhill and settles in low-lying areas, valleys, and basins—exactly where the town center of Hermosa likely sits. While your hilltop property gets exposed to more wind, the valley floor in Hermosa experiences “frost pockets” that are often colder than the hillsides surrounding them on calm nights.
2. Adiabatic Cooling (Elevation Itself):
As air rises in elevation (going from Hermosa town up to your house), it naturally cools. The difference is roughly 3 to 5 degrees Fahrenheit for every 1,000 feet of elevation change. That 700-foot difference is enough for a noticeable temperature drop between your locations.
3. Wind Exposure:
Your property at 4,060 feet on a ridge or hillside is more exposed to the intense, drying Black Hills winds than a location sheltered within the town limits. This wind exposure can dramatically increase plant stress and winter desiccation (drying out).
However, as someone who has lived on this property for almost a decade, I can tell you that we seem to be a micro-micro climate. We actually do not get the cold snaps as severely as the lower areas.
The fact that we are “in the hills and surrounded by trees” fundamentally changes our property’s climate compared to the surrounding open areas. This creates a highly specific forested microclimate that moderates temperatures, leading to the less extreme highs and lows we observe.
It’s a great example of how local geography beats generalized climate data every time.
How Trees and Geography Affect Your Climate
Here are the specific reasons we don’t experience the temperature extremes of the open areas:
1. The “Heat Island” Effect (or lack thereof)
- Outlying Areas (Rapid City, Hermosa town, Belle Fourche): These locations are more developed with more asphalt, concrete, and buildings. These materials absorb heat all day and release it slowly at night, keeping the area warmer and often preventing extreme cold drops.
- Our Property: We are surrounded by trees, soil, and plants. This natural ground cover doesn’t retain heat in the same way, and the canopy of the trees traps cooler air at night.
2. Evapotranspiration (Natural Air Conditioning)
- Trees and plants release moisture vapor into the air through a process called evapotranspiration. This acts like a natural air conditioner. The increased humidity on our property results in cooler daytime temperatures than the dry, open prairie environments nearby.
3. Wind Moderation (The Main Buffer)
- The trees surrounding us acts as a massive, permanent windbreak. This significantly reduces wind speed on our property.
- Reduced Heat Loss in Winter: Less wind means less wind chill and slower heat loss from our home and, critically, from our plants’ buds and stems. This improves the effective hardiness zone for the plants on our property.
- Reduced Heat Gain in Summer: The canopy provides shade, blocking direct sun and keeping summer highs milder than exposed areas.
4. The “Frost Pocket” Dynamic vs. Air Drainage
- Outlying Areas: Suffer from cold air pooling in low basins and plains, leading to lower minimum temperatures (frost pockets).
- Our Property: At 4,060 feet, we are likely on an ‘incline’ where cold air drains away from our immediate planting areas, which helps us avoid those specific extreme lows, even though our general elevation is higher.
Phew- well that just clears it right up, huh? All this to say that there are generalities across the Black Hills, but your property, and even areas within your property are unique. Have some fun figuring it out. I didn’t mean that as a joke… there really can be some fun in all this. Look at it as a mystery. This is all part of the story of your success.