Separate the weather sensors from the protected logger and power electronics. Put temperature and humidity sensing elements in a rain-shedding radiation shield that exchanges air freely. Keep the logger, terminals and regulated supply inside a gasketed enclosure, with sealed entries for external sensor cables.
This arrangement solves two different requirements without compromising either one. The sensors can sample outdoor conditions, while the electronics remain protected from rain, dirt and accidental contact. Choose the enclosure around the installed wiring, service access and heat load, not just the circuit board dimensions.
Give each sensor the exposure it needs
A weather station does not have one environment inside one box. Its sensing elements need different exposure from its electronics.
Temperature and relative humidity sensors need representative ambient air. A sealed enclosure measures its own internal conditions, which change with sunlight, electronics heat and moisture exchange. The article on humidity sensors in sealed enclosures explains that measurement boundary.
Use a light-colored, purpose-designed radiation shield around the external temperature and humidity probe. Its overlapping surfaces should shed rain while allowing airflow around the sensing element. A simple roof blocks overhead rain but does not adequately block reflected sunlight or wind-driven droplets.
Place the shield away from the logger enclosure, power supply, exhaust outlets and sun-heated walls. Do not mount it directly above a warm cabinet. For a general near-ground measurement, a height around 5 ft [1.5 m] is a reasonable starting point. Follow the measurement program's siting requirements when readings must be comparable with other stations.
Rain and wind sensors need their own unobstructed locations. Do not place a rain collector beneath the enclosure roof or a solar panel. Keep wind sensors clear of structures that distort airflow.
A barometric sensor needs access to atmospheric pressure, but not necessarily unrestricted exposure to rain. Select a protected pressure path appropriate to the sensor and its required response time.
Choose the rating for the electronics compartment
Specify the electronics compartment for its actual water and dust exposure. A sheltered installation still needs protection against wind-driven rain, insects and contamination around cable entries.
For an exposed logger cabinet, a gasketed stainless wall-mount enclosure is a practical starting point. The catalog wall-mount enclosures are manufacturer-rated NEMA 4X-type / IP66; not UL listed. Confirm project acceptance before ordering when third-party listing is required.
NEMA 250 and IEC 60529 address enclosure protection, not the accuracy of the weather measurements. Neither rating makes an internal temperature sensor representative of outdoor air. Nor does the cabinet rating transfer automatically to an external probe or radiation shield.
IP66 addresses dust ingress and powerful water jets under its defined test conditions. It is not a submersion rating. Install the cabinet above credible ponding and flood levels rather than treating a rain rating as flood protection.
The completed assembly also depends on every penetration. Cable glands, antenna feedthroughs, blanking plugs and pressure vents must suit the specified protection and installation orientation. Open side holes change the protection boundary, even if a separate cover hides them.
Match the material to the site
Choose 304 stainless steel for most inland outdoor locations where salt and aggressive chemicals are absent. It provides a durable enclosure body without relying on a painted surface for corrosion protection.
Specify 316L stainless steel where salt air, brine or chloride contamination makes corrosion resistance more demanding. It is more resistant to chloride attack than 304, but it is not immune. Deposits, crevices and repeated wetting still matter.
Match mounting hardware, gland bodies and brackets to the exposure. Dissimilar metals in a wet joint can create corrosion problems even when the enclosure itself is suitable. Check the compatibility of isolating hardware without interrupting required electrical bonding.
Stainless steel also changes the communications design. An internal radio antenna may have severely reduced range inside a metal cabinet. Plan an external antenna or another communications route before finalizing the enclosure layout. The article on sealed enclosure antenna feedthroughs covers that penetration separately.
If the installation needs different dimensions or material, custom enclosures let you specify the material, width, height, depth and cutouts. Material selection does not replace the need for a suitable radiation shield around the exposed sensing element.
Size the box around installed equipment and heat
Lay out the logger, terminal blocks, supply, protective devices and cable routes before choosing the outside dimensions. Include connector bodies, mounting hardware and the space needed to remove a memory card or replace a battery.
Two catalog examples show why depth deserves separate attention:
- The 12 x 10 x 6 in 304 stainless wall-mount enclosure has a nominal internal height of 11.91 in, width of 9.91 in and depth of 5.91 in.
- The 12 x 10 x 8 in 304 stainless wall-mount enclosure has a nominal internal height of 11.91 in, width of 9.91 in and depth of 7.91 in.
Those nominal internal dimensions are not the clear component mounting envelope. Account for the mounting panel position, door hardware, gland projection and connector removal space on the drawing. The deeper option adds 2 in [50.8 mm] of nominal internal depth, but verify where that space is available.
Reserve an identified area for expansion rather than specifying an unexplained percentage of spare volume. A future communications module needs mounting area, cable access and power capacity together.
Calculate heat from equipment losses inside the cabinet. For example, a 10 W supply output does not mean 10 W heats the enclosure if most power goes to external devices. Include supply losses and the power dissipated by the internal logger and communications equipment.
Check both direct sunlight and the highest ambient temperature. A low-power logger can still run hot in a small sunlit cabinet. Keep its solar shield separate from the sensor radiation shield: one reduces cabinet heating, while the other protects measurement accuracy. Use the article on solar shields for outdoor electronics enclosures for that heat-load decision.
Plan pressure access without making an air inlet
A pressure equalization vent and a ventilated sensor shield perform different jobs. The vent manages pressure differences across the cabinet wall. The shield exposes a sensing element to moving ambient air.
Do not assume a cabinet vent makes internal humidity measurements representative of outside conditions. A membrane vent has limited airflow and does not provide controlled ambient sampling. It is also not a dependable cooling method or a dehumidifier.
For a barometric sensor inside the cabinet, verify that the pressure path responds quickly enough for the measurement interval. Consider the vent's airflow characteristics, cabinet volume and any restriction between the sensor and vent. Water, dirt or ice on a membrane can slow that response.
Keep pressure ports away from direct wind impingement and suction around sharp edges. For perspective, air moving at 33 ft/s [10 m/s] has about 60 Pa of dynamic pressure at an air density of 1.2 kg/m³. That is approximately 0.6 hPa, enough to affect a pressure reading if the port captures it.
Use the article on enclosure pressure equalization vents to select the cabinet vent without treating it as a substitute for sensor exposure.
Mount and seal the two compartments separately
Mount the cabinet securely and preserve access to its door, terminals and serviceable components. The catalog wall-mount enclosures have hinged gasketed doors, removable mounting panels and wall-mount feet. Check the mounting surface and fasteners against the installed weight and local wind loading.
Prefer downward-facing cable entries where the layout permits. Provide drip loops so water running along a cable does not collect against its gland. Leave enough room below the cabinet to respect the cable manufacturer's minimum bend radius.
Select glands using the actual cable outside diameter, not conductor size or connector diameter. A gland must seal the installed jacket within its specified clamping range. Do not pass several loose cables through a single-hole seal unless the fitting is designed for that arrangement.
Support sensor cables independently of the electrical terminals. The article on cable strain relief for sealed enclosure entries explains how to separate cable retention from sealing. Use the cutouts and cable glands guide for hole and fitting fundamentals.
Choose the communications interface before committing to a long cable run. Check its permitted cable length, voltage drop, outdoor suitability and surge protection requirements. Include connector access and any isolation hardware in the layout.
Before service, isolate electrical supplies using the site's safe work procedure. Dry the cabinet before closing it after wet-weather maintenance. A sound gasket cannot remove moisture trapped during assembly; the article on condensation inside sealed enclosures covers that separate mechanism.
Commission the completed station by comparing its temperature readings with a suitable reference during sun, shade and low-wind periods. If readings rise with cabinet temperature, inspect sensor placement before changing the logger calibration.
Put the exposure boundary on the order
Specify the protected electronics compartment and exposed sensor arrangement separately. A drawing should show which surfaces shed rain, which openings exchange air, and which entries must remain sealed.
| Order item | What to specify |
|---|---|
| Installation environment | Inland or coastal location, salt exposure, expected rain, dust, ambient temperature and direct sunlight |
| Electronics enclosure | Required manufacturer enclosure rating, and whether the project requires third-party listing |
| Material | 304 stainless for most inland sites, or 316L stainless where chloride exposure justifies it |
| Dimensions | Outside height x width x depth, with a checked component layout and service clearances |
| Mounting | Mounting surface, installed weight, bracket arrangement and door access |
| Sensor shield | Separate rain-shedding radiation shield, probe mounting and airflow clearances |
| Cable entries | Cable count, measured jacket diameters, gland details, entry positions and internal projection |
| Pressure measurement | Sensor location, protected pressure path, response requirement and vent installation orientation |
| Communications | Wired interface or external antenna, including feedthrough and protection hardware |
| Thermal design | Internal equipment losses, ambient limits, solar exposure and any separate cabinet sun shield |
| Drawing details | Units, hole sizes, location datums, tolerances and connector removal envelopes |
We build custom enclosures from one piece, with customer-defined material, dimensions and cutouts. For custom work, the approved drawing establishes the layout before manufacture. Keep the sensor shield and its mounting details on the installation drawing, even when they are separate from the enclosure order.
Enclosures in this article
| Enclosure | Material | Outside H x W x D / display | Rating |
|---|---|---|---|
| 12 × 10 × 6 in | 304 stainless | 12 x 10 x 6 in | Rated NEMA 4X / IP66 by the manufacturer; not UL listed |
| 12 × 10 × 8 in | 304 stainless | 12 x 10 x 8 in | Rated NEMA 4X / IP66 by the manufacturer; not UL listed |
Questions
Can temperature and humidity sensors stay inside the sealed logger cabinet?
Not when you need ambient temperature or humidity. The cabinet's air is influenced by sunlight, internal equipment and moisture exchange. Put the sensing element in a separate ventilated radiation shield, while keeping its logger and power electronics inside the protected compartment.
Does a pressure equalization vent make every internal weather sensor accurate?
No. A pressure vent can reduce pressure differences across the enclosure wall, but its airflow is limited. It does not provide representative ambient sampling for humidity or temperature. An internal barometric sensor may use a protected vent path if its pressure response is verified.
Should an outdoor weather station use 304 or 316L stainless steel?
Choose 304 stainless for most inland sites without significant chloride exposure. Consider 316L for coastal salt, brine or similar contamination. Check brackets, fasteners, glands and cleaning practices as well, because the enclosure grade alone does not determine the durability of the installation.
Should I drill side holes so the logger enclosure can breathe?
Usually not. Side holes expose the logger compartment to rain, dirt and insects, and change its protection boundary. Separate the ambient-air sensor from the protected electronics instead. Address cabinet heat through a thermal assessment rather than using sensor ventilation as the cooling strategy.
What space should I allow beyond the logger circuit board?
Account for the mounting panel position, terminal height, connector bodies, cable bends and gland projection. Also allow room to remove connectors and service batteries or memory cards. Nominal internal dimensions describe the enclosure interior, not an unobstructed component mounting envelope.
