diff --git a/sonoff/sonoff.ino b/sonoff/sonoff.ino
index ef9845c81..48145fb2f 100755
--- a/sonoff/sonoff.ino
+++ b/sonoff/sonoff.ino
@@ -125,7 +125,7 @@ int blinks = 201;                           // Number of LED blinks
 uint32_t uptime = 0;                        // Counting every second until 4294967295 = 130 year
 uint32_t loop_load_avg = 0;                 // Indicative loop load average
 uint32_t global_update = 0;                 // Timestamp of last global temperature and humidity update
-float global_temperature = 0;               // Provide a global temperature to be used by some sensors
+float global_temperature = 9999;               // Provide a global temperature to be used by some sensors
 float global_humidity = 0;                  // Provide a global humidity to be used by some sensors
 float global_pressure = 0;                  // Provide a global pressure to be used by some sensors
 char *ota_url;                              // OTA url string pointer
diff --git a/sonoff/support.ino b/sonoff/support.ino
index da79be0e0..f3faa1798 100644
--- a/sonoff/support.ino
+++ b/sonoff/support.ino
@@ -644,7 +644,7 @@ void ResetGlobalValues(void)
 {
   if ((uptime - global_update) > GLOBAL_VALUES_VALID) {  // Reset after 5 minutes
     global_update = 0;
-    global_temperature = 0;
+    global_temperature = 9999;
     global_humidity = 0;
     global_pressure = 0;
   }
diff --git a/sonoff/xsns_21_sgp30.ino b/sonoff/xsns_21_sgp30.ino
index 27d1a43f9..e9c097dc4 100644
--- a/sonoff/xsns_21_sgp30.ino
+++ b/sonoff/xsns_21_sgp30.ino
@@ -89,7 +89,7 @@ void Sgp30Update(void)  // Perform every second to ensure proper operation of th
     }
     return;  // Measurement failed
   }
-  if (global_update) {
+  if (global_update && global_humidity>0 && global_temperature!=9999) {
     // abs hum in mg/m3
     sgp30_abshum=sgp30_AbsoluteHumidity(global_temperature,global_humidity,TempUnit());
     sgp.setHumidity(sgp30_abshum*1000);
@@ -124,7 +124,7 @@ void Sgp30Show(bool json)
   if (sgp30_ready) {
     char abs_hum[33];
 
-    if (global_update) {
+    if (global_update && global_humidity>0 && global_temperature!=9999) {
       // has humidity + temperature
       dtostrfd(sgp30_abshum,4,abs_hum);
     }
diff --git a/sonoff/xsns_31_ccs811.ino b/sonoff/xsns_31_ccs811.ino
index 2624d0b8c..550313b51 100644
--- a/sonoff/xsns_31_ccs811.ino
+++ b/sonoff/xsns_31_ccs811.ino
@@ -62,7 +62,7 @@ void CCS811Update(void)  // Perform every n second
           TVOC = ccs.getTVOC();
           eCO2 = ccs.geteCO2();
           CCS811_ready = 1;
-          if (global_update) { ccs.setEnvironmentalData((uint8_t)global_humidity, global_temperature); }
+          if (global_update && global_humidity>0 && global_temperature!=9999) { ccs.setEnvironmentalData((uint8_t)global_humidity, global_temperature); }
           ecnt = 0;
         }
       } else {